Download - Acids and Metals
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Acids and MetalsLevel E
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Level E Science Topic Book
Earth and Space
Acids andMetals
Glasgow City Council
Designed and Published byEducation Services
Education Improvement ServiceWheatley House
25 Cochrane StreetGlasgow G1 1HL
Phone 0141 287 2000
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ACIDS AND METALS Level E: Science Topic Book
Glasgow 5-14 Science Programme Education Improvement Service 2
Acids and MetalsContents
List of Learning Outcomes
Topic Outline
Activity Support Sheets
Teachers Science Notes
Investigations
Topic Assessment Sheets
Homework Sheets
Glossary
Pupil Checklist
Resources and Safety Issues
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ACIDS AND METALS Level E: Science Topic Book
Glasgow 5-14 Science Programme Education Improvement Service 3
Acids and MetalsLearning Outcomes
TOPIC: Acids and Metals Level E Stage S1/S2
Knowledge and Understanding Strands Changing Materials.
Learning Outcomes:By the end of the unit the pupils should be able to: Level
Measure the pH of common solutions. E
Identify acids, alkalis and neutral solutions from the pH values. E
State that the lower the pH of an acid the greater the acidity; the higher the E
pH of an alkali the greater the alkalinity.
State that acids and alkalis combine to form a neutral solution. E
State that when an acid neutralises an alkali, a salt and water is formed. E
Give real life examples of neutralisation. E
Plan and carry out a practical investigation on the differences in E
acid content in a range of soft drinks.
List metals in order of reactivity with oxygen, water and acid. E
Give examples of how reactivity relates to uses and sources of metals. E
State that more reactive metals can displace less reactive metals from their solutions. E
State that electrolysis can be used to obtain a metal from a solution. E
Describe the effects of electroplating. E
Give examples of how some metals are extracted. E
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ACIDS AND METALS Level E: Science Topic Book
Glasgow 5-14 Science Programme Education Improvement Service 4
The following topic outline suggests activities and examples of ongoing assessments to take forward the Learning
Outcomes listed for this study. To suit their own classes and situations, teachers may want to add to, or adapt some of
these. The main aim, however, is to ensure that children are given the opportunity to overtake the learning outcomes
listed.
Acids and MetalsTopic Outline
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ACIDS AND METALS Level E: Topic Outline
Glasgow 5-14 Science Programme Education Improvement Service 5
Ask pupils what they already knowabout acids (many will mentionburning, corrosion, acid rain,vinegar, citric acid, sour sweets,rotting teeth, etc.). Develop theneed for a way to identify an acid(and later measure the degree ofacidity).Mention the pH scale consisting ofnumbers 0 to 14 which do this. Atthis point you could demonstratesome solutions and their pH using apH meter/probe with interface.Introduce the concept of anindicator and demonstrate the useof Universal Indicator as a way ofindicating the pH of a solution. Nowget pupils to measure the pH of avariety of (safe) common solutionswith Universal Indicator paper (orthe pH meter/probe).
Get pupils to use the values of pHmeasured from Support Sheet 1 tocomplete a table which sorts thesolutions into acids, alkalis andneutral solution.
The above activities will lead toopportunities to discuss what ishappening the further away frompH 7 you go. Teachers should, ifthey have not already done so,introduce the terms acidity/acidicand alkalinity/alkaline as well asacids and alkalis. Get pupils toname some strong acids andalkalis.
Measure the pH ofcommonsolutions.
Identify acids,alkalis andneutral solutionsfrom the pHvalues.
State that thelower the pH of anacid the greaterthe acidity; thehigher the pH ofan alkali thegreater thealkalinity.
Pupils can identify the pH(values, 0 - 14) of asolution from the colour ofpH paper or using a probeor Universal indicatorsolution.
Pupils can state that acidshave a pH value < 7,neutral solutions have apH value = 7, alkalis have apH value > 7.
Pupils can rank substancesin order of acidity/alkalinity using pH values.
Universal Indicator paperwith colour chart, pH meteror probe with interface,variety of commonsolutions e.g. lemon, lime,orange and grapefruitjuices, vinegar, citric acid,cream of tartar, coffee, tea,de-ionised water, saltsolution, Epsom salts, milk,milk of magnesia, washingup liquid, bicarbonate ofsoda, weak ammoniasolution, etc., beakers,safety glasses. (Possiblydroppers and dimple tiles.)
Activity Support Sheet 1.
Activity Support Sheet 1.
Activity Support Sheet 1.
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ACIDS AND METALS Level E: Topic Outline
Glasgow 5-14 Science Programme Education Improvement Service 6
State that acidsand alkaliscombine to form aneutral solution.
State that when anacid neutralises analkali a salt andwater is formed.
Give real lifeexamples ofneutralisation.
Use 10ml syringes (use red andblue tape to identify which syringewill be used for the acid and alkali)to draw 10ml of alkali and put into abeaker (50ml) to which Universalindicator has been added. Nowadd acid (using the red-tapedsyringe) drop by drop, stirringconstantly noting the pH asindicated by the colour change (orpH probe). When the pH reaches 7,point out to pupils the volume ofacid added is the same as the initialvolume of alkali.
Repeat the experiment with alkalibeing added to acid. Point out thatneutralising an acid moves its pHup towards 7 and neutralising analkali moves its pH down towards 7.Use a pH meter or probe withinterface to graph volume versuspH for acid to alkali or alkali to acid.
Pupils can then repeat the aboveexperiment without using indicatorand then evaporate off the water toobtain the salt. (Before evaporation,pupils can check the pH using pHpaper.)
Other examples could be sodiumhydroxide and ethanoic acid,sulphuric acid and ammoniasolution.
Get pupils to find out about theapplications of acid, alkalis andneutralisation using the Find outabout sheet.
Some pupils can researchneutralisation examples such asmilk of magnesia for indigestion,treatment of garden soil, sodiumbicarbonate for acid bee stings andvinegar for alkali wasp stings.Others can research uses of acidsand alkalis such as skin hair care,fruit juices and vinegar andcleaning products. Others still mayresearch the harmful, irritant andcorrosive nature of acids andalkalis and precautions needed.
Syringes (10ml) of HCl andNaOH (same molarity e.g.0.1 M) Beakers, universalindicator, safety glasses.
Activity Support Sheet 2.
Activity Support Sheet 3.
Syringes (10ml) of HCl andNaOH (e.g. 0.1 M.)Beakers, safety glasses pHpaper evaporating basins,Bunsen burners, tripodstands.
Activity Support Sheet 4.
Books, Internet access, CDROMs.
Activity Support Sheet 5.
Pupils can state thatadding acid to alkalilowers the pH and addingalkali to acid raises the pHuntil pH 7 is reached whenthe solution is neutral.
Pupils can state that theneutral solution formed isa salt and water.
Pupils can identify someacids, e.g. vinegar, lemonjuice.
Pupils can identify someeveryday uses of acids,e.g. in foods, medicines,cleaning materialstreatment of bee/waspstings, treatment of soil,etc.
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ACIDS AND METALS Level E: Topic Outline
Glasgow 5-14 Science Programme Education Improvement Service 7
Give real lifeexamples ofneutralisation,contd.
Plan and carry outa practicalinvestigation onthe differences inacid content in arange of softdrinks.
After their research you can getpupils to try out one or twoexamples as experiments. Get themto plan and record what they do.For example treatment forindigestion; pupils take 20 ml of HCland add to beaker, add someuniversal indicator, then addindigestion powder or indigestiontablets to beaker stir and watchwhat happens to pH. Ask pupilswhat type of reaction is taking placeand which type of chemical must bepresent in the indigestion powder.
Treatment of garden soil (farmland).Mention acid rain and its effect onraising soil acidity which can affectplant growth. Repeat the activityabove but replacing indigestionpowder with lime.
Give pupils a variety of soft drinksto test. Pupils can use pH paper orbetter still a pH meter or probe withinterface.
Use 0.1 M HCl, stirring rods,beakers, selection ofindigestion tablets/powders, universalindicator.
Activity Support Sheet 6.
As above, but replaceindigestion powder withlime.
Activity Support Sheet 6.
Various soft drinks eachwith a different acid contentare required, universalindicator, pH paper, pHmeter, beakers, measuringcylinders, syringes.
I am a Scientist
investigation sheets.
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ACIDS AND METALS Level E: Topic Outline
Glasgow 5-14 Science Programme Education Improvement Service 8
List metals inorder of reactivitywith oxygen,water and acid.
Give examples ofhow reactivityrelates to usesand sources ofmetals.
Burn samples of magnesium andcopper to demonstrate theirreaction with oxygen and toillustrate either end of the reactivityseries. Pupils can look at display ofmetals that have been left exposedto oxygen for a month and compareit with fresh samples (arrange thedegree of corrosion to reinforce thereactivity of the metals).
Teacher demonstration of metals inwater using small samples ofpotassium, sodium (caesium can beshown using a video). Pupilsshould then try out samples ofcalcium, magnesium, aluminium,zinc, iron, tin, copper (note theorder).
Get pupils to repeat theirexperiments using dilute HCLinstead of water (Ca is veryreactive!). If any pupil (or teacher)has a piece of gold they are willingto add to acid that can be tested aswell. Include lead in the metalsamples to be tested.Pupils can test a sample of the gaswhich is generated to identify it ashydrogen. (The test for hydrogen iscovered in the Unit ChemicalReactions.) Pupils find it interestingto see that there is hydrogen gasgiven off by the action of a metal.
Discuss the experiments withpupils and then complete thereactivity series table. Point out thatmetals near the top react withoxygen and water; metals near themiddle react with acid but notwater and metals near the bottomdo not react at all.
Get pupils to research everydayuses of metals (and dates ofdiscovery) and how this relates totheir reactivity and use. Pupils canalso find out where different metalscome from. Pupils can write reportindividually or in a group andpresent work/or display work tothe rest of the class.
Safety screen, Bunsenburner, mat, tongs,magnesium ribbon, copperfoil; samples of metals,fresh and partially corroded e.g. Mg, Zn, Fe, Sn, Cu, Ag,Au.Activity Support Sheet 7.
Safety screen, trough withwater, samples of, K, Na, Ca,Mg, Al, Zn, Fe, Sn, Cu, Pb, testtubes and racks, safetygoggles.Activity Support Sheet 8.
Dilute HCl, CD-ROMs, MultiMedia Science School hasvideo clips of the group onemetals, also CrocodileChemistry will allow you toshow animations of theexperiments.Activity Support Sheet 9.
Activity Support Sheet 10.
Books, Internet access, CDROMs.Activity Support Sheet 11.
Pupils should be able to listmetals in the correct orderof reactivity: potassium,sodium, calcium,magnesium, aluminium,zinc, iron, tin and copper.
Pupils can give examplesthat show how reactivity ofa metal is related to its use.
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ACIDS AND METALS Level E: Topic Outline
Glasgow 5-14 Science Programme Education Improvement Service 9
State that morereactive metalscan displace lessreactive metalsfrom theirsolutions.
State thatelectrolysis can beused to obtain ametal from asolution.
Describe theeffects ofelectroplating.
Give examples ofhow some metalsare extracted.
Get pupils to use metals to displaceless reactive metals from theirsolutions. Give them a solution of aless reactive metal and a morereactive metal in metallic form toinsert.The inserted metal disappears andthe metal originally in solution isdeposited. For example - zinc metalinto a solution of copper sulphate.Iron metal into a solution of coppersulphate. Magnesium metal into asolution of nickel sulphate.Point out that the new metal hasbeen formed and that the originalmetal that was placed in solution isnot present any longer. Highlightany change in colour of the originalsolutions and possible change intemperature.
Let pupils carry out the electrolysisof copper (II) chloride and observeand record the formation ofproducts at the electrodes particularly the deposition ofcopper.Demonstrate the electrolysis ofmolten lead bromide. Show a videoclip for this experiment.
Safety Note: Use low voltage incopper chloride experiment toprevent build up of chlorine gas;
ventilate room while carrying outexperiment.
Get pupils to carry outelectroplating of a steel nail withnickel or with copper. Point out thatit is possible to electroplate onemetal with another usingelectrolysis.Discuss with pupils how thismethod is used to protect metalsfrom corrosion.
Get pupils to research theextraction of metals from their orese.g. Iron, aluminium, copper, lead,gold, silver.
Zinc, iron and magnesiummetals. Copper sulphatesolution and nickelsulphate solution.Or any other suitablecombinations.Small beakers, stirring rods,(or boiling tubes) safetygoggles.
Activity Support Sheet 12.
Solution of copper (II)chloride, carbon electrodes,power pack, leads, beakers,safety goggles.
Lead bromide and suitableapparatus for carrying outthe electrolysis experiment.
Activity Support Sheet 13.
Solutions of copperchloride and nickelsulphate, power pack,leads, carbon electrodes,steel nails, beakers,crocodile clip.
Activity Support Sheet 14.
Books, Internet access, CDROMs.Activity Support Sheet 15.
Pupils can state that metalshigher in the reactivityseries can displace metalslower in the series fromtheir solutions.
Pupils state thatelectrolysis is a method ofextracting metals fromsolutions.
Pupils can describe theeffects of electroplatingone metal with anotherusing electrolysis.
Pupils can explain theextraction of some metalsfrom their ores.
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ACIDS AND METALS Level E: Science Topic Book
Glasgow 5-14 Science Programme Education Improvement Service 10
Acids and MetalsActivity Support Sheets
Primarily the pupil worksheets support children through practical activities or experiments. A few reinforce knowledge
and understanding.
The Glasgow 5-14 Science Programme promotes an enquiry-based approach to learning which is characterised by first-
hand experience. Great care has been taken, therefore, not to place an over-reliance on worksheets.
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ACIDS AND METALS: Level E: Activity Support Sheet
Name
Glasgow 5-14 Science Programme Education Improvement Service 11
1
Measuring pHUse the table here to record your values for the pH of the solutions youtested. Write the name of your solution in the left hand column the firsttwo have been done for you.
Acid, alkali or neutral
Use the values of pH to decide if the solution is an acid, alkali or neutral and write your result in thelast column.
solution
Hydrochloric acid
Sodium hydroxide
pH acid or alkali or neutral
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ACIDS AND METALS: Level E: Activity Support Sheet
Name
Glasgow 5-14 Science Programme Education Improvement Service 12
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Adding acid to alkaliAdd the alkali to the beaker first and use the table to record how the pHchanges as you add acid.
Use the words in the word bank to complete the sentence about adding acid to alkali.
When acid is added to , the pH of the mixture
until the solution is
Wordbank
neutral decreases alkali
Volume of alkali 10 ml
2
4
6
8
10
volume of acid added (ml) pH
acid alkali
universal indicator
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ACIDS AND METALS: Level E: Activity Support Sheet
Name
Glasgow 5-14 Science Programme Education Improvement Service 13
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Adding alkali to acidAdd the acid to the beaker first and use the table to record how the pHchanges as you add alkali.
Use the words in the word bank to complete the sentence about adding acid to alkali.
When alkali is added to , the pH of the mixture
until the solution is
Wordbank
neutral increases acid
Volume of acid 10 ml
2
4
6
8
10
volume of alkali added (ml) pH
acid alkali
universal indicator
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ACIDS AND METALS: Level E: Activity Support Sheet
Name
Glasgow 5-14 Science Programme Education Improvement Service 14
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Making salt
acid alkali
acid + alkali a salt + water
Space for diagram
Describe how hydrochloric acid and sodiumhydroxide can be used to make common salt(sodium chloride).
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ACIDS AND METALS: Level E: Activity Support Sheet
Name
Glasgow 5-14 Science Programme Education Improvement Service 15
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Finding out about neutralisationThis sheet will help you to plan how you are going to carry out your research, record your findings andpresent a report to your class.
1. Where are you going to find the information you need?Write the names of the books, CD ROMs or web sites you use in this box.Your teacher may be able to help you with this.
2. What information are you going to need?Use this box to write down any questions you want to find the answers to, e.g.How is indigestion cured? How are bee and wasp stings treated?How do gardeners treat soil?
3. Now write down all of the information you have found.Do this in your jotter or on a separate piece of paper.
4. How are you going to present your findings?You could use a poster, a written report, or a report you read out to your class.Be creative what about a poem, a play or a presentation?
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ACIDS AND METALS: Level E: Activity Support Sheet
Name
Glasgow 5-14 Science Programme Education Improvement Service 16
Trying it outCollect some dilute hydrochloric acid in a test tube and add a few dropsof Universal Indicator.Crush an indigestion tablet. Add the crushed tablet bit by bit to the acid(stirring all the time) until the acid is neutralised.Use the space below to plan out your experiment.
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Treating the soil
Collect a small amount of soil, add some water and a few drops of Universal Indicator solution.Change the pH of the soil to make it alkaline good for roses!Use the space below to plan out your experiment.
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ACIDS AND METALS: Level E: Activity Support Sheet
Name
Glasgow 5-14 Science Programme Education Improvement Service 17
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Reactions of metals with oxygenCompare the appearance of each fresh metal sample with how it looksafter being exposed to oxygen for a month.Describe the differences as accurately as you can.
The most reactive metal is the most corroded.Place the metals below in order of how reactive they are.
less reactive more reactive
magnesium iron tin
gold zinc copper
name of metal fresh after a month's exposure
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ACIDS AND METALS: Level E: Activity Support Sheet
Name
Glasgow 5-14 Science Programme Education Improvement Service 18
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Reactions of metals with waterDescribe how each metal reacts with water as accurately as you can.
name of metal decription of reaction with water
Place the metals below in order of how reactive they are in water.
less reactive more reactive
magnesium iron caesium
potassium sodium zinc calcium
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ACIDS AND METALS: Level E: Activity Support Sheet
Name
Glasgow 5-14 Science Programme Education Improvement Service 19
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Reactions of metals with acidDescribe how each metal reacts with acid as accurately as you can.
Place the metals below in order of how reactive they are in acid.
less reactive more reactive
magnesium iron tin
copper aluminium zinc lead
name of metal decription of reaction with acid
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ACIDS AND METALS: Level E: Activity Support Sheet
Name
Glasgow 5-14 Science Programme Education Improvement Service 20
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Reactivity SeriesComplete the table below using the following metals:aluminium, zinc, potassium, sodium, clacium,magnesium, gold, slver, iron, tin, lead. copper, caesium.
react with water metal react with acid
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ACIDS AND METALS: Level E: Activity Support Sheet
Name
Glasgow 5-14 Science Programme Education Improvement Service 21
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Finding out about metalsThis sheet will help you to plan how you are going to carry out your research, record your findings andpresent a report to your class.
1. Where are you going to find the information you need?Write the names of the books, CD ROMs or web sites you use in this box.Your teacher may be able to help you with this.
2. What information are you going to need?Use this box to write down any questions you want to find the answers to, e.g.Why is copper used for household plumbing? Whats so special about gold?
3. Now write down all of the information you have found.Do this in your jotter or on a separate piece of paper.
4. How are you going to present your findings?You could use a poster, a written report, or a report you read out to your class.Be creative what about a poem, a play or a presentation?
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ACIDS AND METALS: Level E: Activity Support Sheet
Name
Glasgow 5-14 Science Programme Education Improvement Service 22
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Using reactivity displacementSet up the two experiments shown here.In the space below each diagram, record any changes you see asaccurately as possible.
zinc sulphate solution
copper zinc
copper sulphate solution
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ACIDS AND METALS: Level E: Activity Support Sheet
Name
Glasgow 5-14 Science Programme Education Improvement Service 23
at the positive electrode at the negative electrode
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Splitting upUse this sheet to record your observations of the electrolysisof copper chloride.
+
positive electrode negative electrode
250 ml beaker
Power PackDC Supply
copper chloride
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ACIDS AND METALS: Level E: Activity Support Sheet
Name
Glasgow 5-14 Science Programme Education Improvement Service 24
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ElectroplatingUse this sheet to record your observations of electroplatinga steel nail with copper.
+
positive electrode steel nail
Power PackDC Supply
copper sulphate
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ACIDS AND METALS: Level E: Activity Support Sheet
Name
Glasgow 5-14 Science Programme Education Improvement Service 25
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Finding out about metal extractionThis sheet will help you to plan how you are going to carry out your research, recordyour findings and present a report to your class.
1. Where are you going to find the information you need?Write the names of the books, CD ROMs or web sites you use in this box.Your teacher may be able to help you with this.
2. What information are you going to need?Use this box to write down any questions you want to find the answers to, e.g.What is an ore? What happens to it in a blast furnace?
3. Now write down all of the information you have found.Do this in your jotter or on a separate piece of paper.
4. How are you going to present your findings?You could use a poster, a written report, or a report you read out to your class.Be creative what about a poem, play or presentation?
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ACIDS AND METALS Level E: Teachers Science Notes
Glasgow 5-14 Science Programme Education Improvement Service 26
Acids and MetalsTeachers Science Notes
Many teachers do not feel confident to teach science outwith their own specialist area. They are concerned that their own
limited knowledge restricts what they should be teaching. The materials in this programme are designed to help increase
teacher confidence.
These notes provide a summary of the science ideas covered in this topic and relate directly to the suggested learning
activities.
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ACIDS AND METALS Level E: Teachers Science Notes
Glasgow 5-14 Science Programme Education Improvement Service 27
Acids and MetalsTeachers Science Notes
AcidsPupils often describe acids as being dangerous and able to dissolve things like the blood from the creature in Alien. You
can have a good session exploring the misconceptions.
Acids are really compounds which generate hydrogen ions when dissolved in water. The degree of acidity is measured by
the hydrogen ion concentration called the pH scale.
Acids and alkalisYou can describe acids as substances which like to give hydrogen. The opposite of an acid is a base a substance which
likes to accept hydrogen. In this unit, we only mention alkalis - which are bases that are soluble in water. Neutral substances
do not like to give or accept hydrogen. A solution is acidic, alkaline or neutral.
pH = 4
pH = 5
pH = 6
pH = 7
pH = 8
pH = 9
pH = 10
pH ScaleA good way to help pupils remember what they are measuring is to call the
pH scale the Power of Hydrogen scale. Values of pH less than 7 indicate the
solution is an acid; a value greater than 7 indicates the solution is an alkali; a
value equal to 7 indicates a neutral solution. (All substances tested in this
unit will be in solution.) A strong acid will have a pH value of 0 and a strong
alkali will have a pH value of 14.
The pH number of a solution can be determined by colour matching using
Universal Indicator which comes as a liquid or in strips of paper which has
been impregnated with Universal Indicator called Universal Indicator
Paper or, more normally, pH paper.
NeutralisationAcids and alkalis can cancel each other out in a process called neutralisation. This has many useful applications which
include:
Treating bee stings (venom is acidic) with sodium bicarbonate and wasp (venom is alkaline) stings with vinegar.
Indigestion tablets (alkaline) to cure acid indigestion e.g. milk of magnesia.
Lime (alkali) used by farmers to raise soil pH.
All neutralisation processes move the pH of an acid or alkali towards 7. The products of all neutralisation reactions include
a salt and water. (With a carbonate the gas carbon dioxide is also formed.) To name the salt, use the metal from the alkali
for the first part and the name of the acid for the second part, e.g. reacting sodium hydroxide and Hydrochloric Acid
together would give you sodium chloride. Testing the pH of salts will show that not all salts are neutral.
Sample of colours of UniversalIndicator showing pH values 4-10.
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ACIDS AND METALS Level E: Teachers Science Notes
Glasgow 5-14 Science Programme Education Improvement Service 28
METALS REACTION WITHOXYGENREACTION WITH
WATERREACTION WITH
ACIDREACTION WITHCOMPOUND
Potassium
Sodium
Lithium
Calcium
Magnesium
Aluminium
Zinc
Iron
Nickel
Tin
Lead
Copper
Silver
Mercury
Gold NO
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Reactivity SeriesThe reactivity series is a list which places metals in order of their readiness to take part in chemical reactions. Metals at the
top react faster with water and dilute acid and burn more vigorously in oxygen. See the table below for the reactivity of
common metals.
Metals higher up the table can also push out lower ones from compounds. This is called displacement.
When a metal higher up the reactivity series is added to a solution containing a metal lower in the series, the lower metal
is forced out of the solution and is deposited the higher up metal replaces it in solution.
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ACIDS AND METALS Level E: Teachers Science Notes
Glasgow 5-14 Science Programme Education Improvement Service 29
The reactivity series affects how metals are used. Metals like
lead and copper are used for roofs and piping because they
do not react easily.
Iron is common and is used to make many things, but it has
to be protected from corrosion (electroplating).
Very unreactive metals like gold and silver are used for
jewellery because they stay shiny.
Electroplating of MetalsElectroplating is the coating of an object (which must be a conductor) with a metal. The object to be coated is attached to
the negative electrode. The positive electrode would be the coating metal (otherwise the coating metal comes out of solution).
These would then be placed in a solution of the coating metal. An electric current passes through the solution due to the
movement of electrons and ions in the solution. This is also the basis of the operation of a battery.
The Glasgow Science Centre has a titanium roof.
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ACIDS AND METALS Level E: Teachers Science Notes
Glasgow 5-14 Science Programme Education Improvement Service 30
METAL EXTRACTED ORE USE
copper chalcopyriteElectrical wiring good conductor
of electricity
aluminium bauxiteCans; aircraft bodies
because of its lowdensity
zinc smithsoniteUsed to protect iron
by galvanising
magnesium magnesium chlorideFireworks; flares;
medicines
tin cassiteriteSolder; anodising
steel
iron haematite
Iron is used to makesteel girders and steel to
reinforce concretebecause it is strong
under tension
Extraction of MetalsElectrolysis is a method of extraction using electricity to split up a metal ore. This method of extraction is only used to
extract the metals from the top of the reactivity series. The metal always forms around the negative electrode during
electrolysis (because metal ions are positive).
Less reactive metals are extracted using heat and carbon (coke) usually in a furnace. The extraction of iron is carried out in
a blast furnace using this method. The very unreactive metals such as gold and silver have been known since earliest
civilisation and are often found in their metallic state.
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ACIDS AND METALS Level E: Investigations
Glasgow 5-14 Science Programme Education Improvement Service 31
Acids and MetalsInvestigations
Although investigating is an activity that crosses the curriculum, it has special significance for
science. First-hand investigations are central to the way in which young children learn science,
providing opportunities to plan fair tests, make observations, hypothesise, predict, collect
evidence, research, survey and discuss. Through such means, opportunities arise to infer,
deduce, calculate, draw conclusions from evidence, make judgements and debate important
issues. Characteristics such as curiosity, responsibility, perseverance, cooperation, attention
to detail and divergent thinking are also encouraged.
Environmental Studies 5-14 National Guidelines (2000)
Open-ended investigations are proven to increase pupil motivation, thinking skills and knowledge and understanding.
The investigative skills of planning, fair testing, observing, measuring, recording, reporting and evaluating are best promoted
through investigative work and to this end, this topic includes a topic investigation.
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ACIDS AND METALS Level E: Investigations
Glasgow 5-14 Science Programme Education Improvement Service 32
By the time pupils reach S1/S2, they will have, with the support of their teachers, developed a range of investigative skills.
If the Glasgow Science Programme has been used throughout the primary stages, almost all pupils will have achieved skills
at level C by P7 and most will be working at level D. During S1/S2, therefore, pupils should concentrate on the skills at D to
F. The teacher will decide which level is most appropriate for each pupil. The progression in S1/S2 from Level D to Level F
is reflected in the difficulty of the planning and recording sheet for the topic. However, to ensure differentiation, the I am a
Scientist sheets from topics at other levels can be used.
This section of the booklet offers teachers advice on developing the skill areas of
Preparing for tasks
Planning
Predicting
Fair testing
Carrying out tasks
Observing and measuring
Recording
Reviewing and reporting on tasks
Reporting and presenting
Interpreting and evaluating
It also suggests a topic investigation that will promote scientific enquiry.
It is important that when carrying out investigations pupils are encouraged to suggest ways of answering the investigating
question.
The accompanying Investigation Planning and Recording Sheet I am a Scientist takes pupils through a structure for
investigation and allows them to systematically record their findings. A separate sheet is included for each skill strand.
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ACIDS AND METALS Level E: Investigations
Glasgow 5-14 Science Programme Education Improvement Service 33
Preparing for TasksPreparing for tasks includes understanding a task and planning a practical activity, making predictions and
undertaking fair testing.
By the time pupils reach S1, they will have been working at level D and should be able, with help from the teacher,
to contribute to the whole investigative process from planning to evaluation. Teachers in secondary schools
should be aware that the 5-14 programme is not an end point but a pathway to Standard Grade courses in S3/S4
and skills development should lead naturally to pupils acquiring those skills required for Standard Grade
investigations. Even so, pupils at the beginning of S1 will require more support than those at the end of S2.
The following outlines the progression in skills for preparing for tasks for levels D to F and includes the
investigative skill objectives from Standard Grade (all sciences).
Level DPupils are able to:
identify two or three questions to investigate
provide reasons for planning decisions
include fair testing in planning by changing one
factor
show awareness of the significance of variables
Level EPupils are able to:
identify a number of questions to investigate
plan a valid and reliable test for a given hypothesis
Level FPupils are able to:
formulate a testable hypothesis
plan an appropriate strategy to investigate a
hypothesis
Standard GradePupils are able to:
demonstrate understanding of the problem posed (G1)
state the aim of the investigation (G2)
articulate a testable hypothesis (G3)
suggest a broad strategy to adopt (G4)
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ACIDS AND METALS Level E: Investigations
Glasgow 5-14 Science Programme Education Improvement Service 34
Carrying out TasksCarrying out tasks includes observing, measuring and recording findings.
By the time pupils reach S1, they will have been working at level D and should be able, with help from the teacher,
to contribute to the whole investigative process from planning to evaluation. Teachers in secondary schools should
be aware that the 5-14 programme is not an end point but a pathway to Standard Grade courses in S3/S4 and
skills development should lead naturally to pupils acquiring those skills required for Standard Grade investigations.
Even so, pupils at the beginning of S1 will require more support than those at the end of S2 although their repertoire
of measurement skills should be quite well developed on entry to secondary.
The following outlines the progression in skills for carrying out tasks for levels D to F and includes the investigative
skill objectives from Standard Grade (all sciences).
Level DPupils are able to:
make an appropriate series of accurate
measurements
select an appropriate way of recording findings
Level EPupils are able to:
select and use appropriate forms of graphical
presentation
Level FPupils are able to:
make a series of measurements of the input and
outcome variables
make their own selection and be able to use
appropriate recording and presentation
Standard GradePupils are able to:
adopt appropriate and safe procedures (E1)
identify the input variable to be used and alter it
over a suitable range (E2)
control all relevant variables as necessary (E3)
make valid, reliable measurement of the outcome
variable (E4)
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ACIDS AND METALS Level E: Investigations
Glasgow 5-14 Science Programme Education Improvement Service 35
Reviewing & Reporting on TasksReviewing and reporting on tasks includes reporting and presenting as well as interpreting and evaluating results
and processes.
Scientific investigations lend themselves to reporting and presenting information to fellow pupils. This forces
children to clarify their thinking and knowledge. Explaining to others is at the heart of constructivism and is a very
powerful way to learn developing metacognition in pupils.
The following outlines the progression in skills for reviewing and reporting on tasks for levels D to F and includes
the investigative skill objectives from Standard Grade (all sciences).
Level DPupils are able to:
make an organised report of an investigation using
appropriate illustrations
provide explanations related to scientific
knowledge
draw conclusions consistent with the findings
identify limitations of the approach used.
Level EPupils are able to:
write a structured report of an investigation using
appropriate illustrations and vocabulary
establish links between the results and the original
hypothesis
suggest improvements to the approach used
Level FPupils are able to:
evaluate a range of aspects of the investigation
Standard GradePupils are able to:
tabulate results with appropriate headings and units
of measurement (RR1)
present the results on a graph or chart (RR2)
draw a valid conclusion inter-relating the appropriate
variables (Ev1)
use results to evaluate the original hypothesis (Ev2)
describe how the investigation was carried out (RR3)
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ACIDS AND METALS Level E: Investigations
Glasgow 5-14 Science Programme Education Improvement Service 36
Acids and MetalsTopic Investigation: Teacher InformationWhich drink is the most acidic?
Preparing for tasksWhat will be measured? The pH (the acidity) of the drink, type (name ) of drink.
How will it be measured? Using pH paper or universal indicator or because of the colour of some of the
soft drinks a pH meter may be more suitable.
What needs to be kept the same? The volume of soft drink.
Make a hypothesis. There is no obvious trend to determine. Pupils may wish to take the
investigation further by looking at label contents or compare still and fizzy
drinks.
Carrying out tasksHow will measurements be recorded? Use a table headings could be:
Name of soft drink and pH value
Reviewing and reporting on tasksMake a graph A bar graph in this case.
Draw a conclusion Which drink gave the highest/lowest pH?
Was the prediction correct?
Can you explain? Drinks with acid give a low pH. Milk is alkaline, although if it is left out for a few
days its pH decreases. This is a possible alternative investigation.
Write a report. Include a plan, diagram of apparatus , table of measurements , and description
of procedure.
If another pupil could repeat the investigation from the report, it is good.
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ACIDS AND METALS Level E: Investigations
Glasgow 5-14 Science Programme Education Improvement Service 37
a science investigation report
by:
Preparing the taskTitle
(Investigative question)
What Iwill change
(Input variable)
What will bemeasured?(Outcome variable)
How will it bemeasured?
(Description of apparatus)
What do I thinkwill happen?
(Hypothesis)
What I will do tokeep the test
fair?(Control of variables)
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ACIDS AND METALS Level E: Investigations
Glasgow 5-14 Science Programme Education Improvement Service 38
Carrying Out the TaskMy table of results
A graph of my results
Comments (e.g. relationships between variables)
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ACIDS AND METALS Level E: Investigations
Glasgow 5-14 Science Programme Education Improvement Service 39
Reviewing & Reporting on the TaskDiagram of my apparatus
Description of what I did:
Summary of what I found out (Conclusion/links to hypothesis):
Description of improvements (Evaluate at least two aspects):
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Acids and Metals
ACIDS AND METALS Level E: Assessment Sheets
Assessment Sheets
The topic outline offers suggestions for ongoing assessment. The following sheets are provided to aid summative assessment
of pupils knowledge and understanding. They can be copied and used during the topic or at the end of the topic if the
teacher prefers.
The pupil evaluation sheets ask pupils to think about how much they have learned and what areas they enjoyed. These
sheets give the pupils an opportunity to give feedback to the teacher and provide some evidence for the teacher on the
pupils developing attitudes.
Glasgow 5-14 Science Programme Education Improvement Service 40
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ACIDS AND METALS Level E: Science Topic Book
Glasgow 5-14 Science Programme Education Improvement Service 41
Evaluation Sheet
I have completed a topic about:
These are the things I have learned and can do better:
Next time I do science I want to get better at:
Shade in the box to show how much you enjoyed the Topic.
Comment:
very poor very good
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ACIDS AND METALS: Level E: Assessment Sheets
Name
Use this page to record things you want to get off your chest!
Some dentists would like to see fizzy drinks banned because they damage teeth. Others wantthe acid content reduced or the drinks to cost more. The makers dont want the drinks banned.They are also worried that changing the acid content will affect the taste. What do you think?
Find out some information about the acid content in drinks. Revise what you know about teeth andtooth decay.
Give your opinion on the issue below.
Glasgow 5-14 Science Programme Education Improvement Service 42
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ACIDS AND METALS: Level E: Assessment Sheet
Name
Glasgow 5-14 Science Programme Education Improvement Service 43
1
What colour is pH paper when in an acid?
What colour is pH paper when in an alkali?
What colour is pH paper when in neutral substances?
Name two common solutions which are acidic.
Name two common solutions which are alkali.
Name two laboratory acids.
Name two laboratory alkalis.
KU
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ACIDS AND METALS: Level E: Assessment Sheet
Name
Glasgow 5-14 Science Programme Education Improvement Service 44
2KU
In an experiment, Caitlin was asked toorganise some solutions into threegroups:
What name could be given to a solution in:
Group A?
Group B?
Group C?
What chemical could Caitlin use to test the pH of liquids?
What happens to the pH of an acid as it is neutralised?
What happens to the pH of an alkali as it is neutralised?
A
B
C
less than 7
7
more than 7
GROUP pH
pH 1
pH 2
pH 3
pH 4
pH 5
pH 6
pH 7
pH 8
pH 9
pH 10
pH 11
pH 12
pH 13
pH 14
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ACIDS AND METALS: Level E: Assessment Sheet
Name
Glasgow 5-14 Science Programme Education Improvement Service 45
3KU
Taking indigestion remedies to cure acid indigestion is an example of neutralisation.What two things are always made when neutralisation takes place?
+
Describe another example of neutralisation.
Rearrange the following metals in order of reactivity; putting the most reactive on top.
zinc
copper
calcium
tin
sodium
aluminium
potassium
magnesium
iron
METAL ORDER
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ACIDS AND METALS: Level E: Assessment Sheet
Name
Glasgow 5-14 Science Programme Education Improvement Service 46
4KU
Gold and silver have been used to make jewellerysince the earliest times.Other metals such as calcium and aluminium wereunknown until approximately 200 years ago.
Explain why gold and silver were among the first metals to be discovered.
Explain why calcium and aluminium were not discovered until recent times.
Some metals were added to solutions as shown below. In the box provided state which metal is leftafter the reaction takes place.
iron + copper sulphate
tin + zinc sulphate
magnesium + nickel chloride
METAL FORMED
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ACIDS AND METALS: Level E: Assessment Sheet
Name
Glasgow 5-14 Science Programme Education Improvement Service 47
5KU
Describe what happens when copperchloride is electrolysed.Remember to describe what happens at theelectrodes.
Space for diagram
Screws, which are to be used outside, are often electroplated with zinc.Describe how a steel screw can be electroplated.
Why is it useful to use zinc-plated screws outdoors?
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ACIDS AND METALS: Level E: Assessment Sheet
Name
Glasgow 5-14 Science Programme Education Improvement Service 48
6KU
Describe two different extraction processesfor any metals you have studied in thistopic.Method 1:
Space for diagram
Space for diagram
Method 2:
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ACIDS AND METALS: Level E: Assessment Sheet
Name
Glasgow 5-14 Science Programme Education Improvement Service 49
7PS
Jeff added dilute potassium hydroxide slowly to dilute sulphuric acid. After he added each drop, hetested the pH of the solution and recorded the results in a table.
Draw a line graph of Jeffs results.
How many drops of potassium hydroxide neutralised the acid?
0
2
4
6
8
10
12
2
3
4
5
6
7
8
NUMBER OF DROPS pH OF SOLUTION
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ACIDS AND METALS: Level E: Assessment Sheet
Name
Glasgow 5-14 Science Programme Education Improvement Service 50
8PS
Name the acid and alkali which could be used to prepare solutions of each of the following salts.
Experiments were set up to investigate the rate of reaction of six metals, A, B, C, D, E and F with dilutehydrochloric acid, oxygen and water. The results are shown below.
Place the six metals in order of reactivity. (Start with the least reactive.)
magnesium sulphate
sodium chloride
calcium nitrate
less reactive more reactive
A
B
C
D
E
F
no reaction
vigorous reaction
slow reaction
explosive reaction
slow reaction
vigorous reaction
no reaction
slow reaction
slow reaction
vigorous reaction
no reaction
fast reaction
no reaction
slow reaction
no reaction
very quick reaction
no reaction
quick reaction
METAL REACTION WITH ACID REACTION WITH WATER REACTION WITH OXYGEN
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Acids and Metals
ACIDS AND METALS Level E/F: Homework Sheets
Homework Sheets
Improving Science Education 5-14 (1999), section 2.3 makes the following statement about homework:
Science homework was rarely given in primary schools and was not sufficiently purposeful or challenging in
secondary schools.
The following homework sheets are designed to address this need. The questions are intended to offer the opportunity for
pupils to think, write extended answers and try some simple practical tasks. Teachers should ensure that pupils are given
any necessary safety advice in relation to the practical tasks (e.g. do not drink the water after adding salt, if the tumbler
breaks, ask an adult to help clean the broken glass).
Although entitled Homework Sheets, these questions can be used to check pupils understanding and can be used in
class as well as at home. The material supplied here is not exhaustive. Teachers can and should use other sources for
homework in the course of their teaching.
Glasgow 5-14 Science Programme Education Improvement Service 51
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ACIDS AND METALS: Level E: Homework Sheet
Name
Glasgow 5-14 Science Programme Education Improvement Service 52
1
The table below was copied from Universal Indicator paper (pH paper).
1pH 2 3 4 5 6 7 8 9 10 11 12 13 14
red
pink
oran
ge
beig
e
yello
w
lime
gree
n
gree
nne
utra
l
slig
htly
aci
d
very
aci
d
slih
tly a
lkal
ine
very
alk
alin
e
dark
gre
en
turq
uois
e
pale
blu
e
blue
dark
blu
e
viol
et
purp
le
Describe how the pH of a solution can be measured using pH paper.
What colours does pH paper turn in acids?
What range of pH values indicates a solution is acidic?
What range of pH values indicates a solution is alkaline?
What colour does pH paper turn in neutral solutions?
What is the pH of neutral solutions?
Name one neutral solution.
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ACIDS AND METALS: Level E: Homework Sheet
Name
Glasgow 5-14 Science Programme Education Improvement Service 53
1a
The table below was copied from Universal Indicator paper (pH paper).
Describe how the pH of a solution can be measured using pH paper.
What colours does pH paper turn in acids?
What range of pH values indicates a solution is acidic?
What range of pH values indicates a solution is alkaline?
What colour does pH paper turn in neutral solutions?
What is the pH of neutral solutions?
Name one neutral solution.
1pH 2 3 4 5 6 7 8 9 10 11 12 13 14
red
pin
k
ora
nge
bei
ge
yello
w
lime
gre
en
gre
enne
utra
l
slig
htly
aci
d
very
aci
d
slih
tly a
lka
line
very
alk
alin
e
da
rk g
reen
turq
uois
e
pa
le b
lue
blu
e
da
rk b
lue
viol
et
pur
ple
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ACIDS AND METALS: Level E: Homework Sheet
Name
Glasgow 5-14 Science Programme Education Improvement Service 54
2
The following is a report given by SEPA to a fish farmer.
Describe how you would use Universal Indicator or pH paper to measure the pH of the water.
Give a name of a substance which could be used to neutralise the water.
Explain what is meant by neutralisation.
What happens to the pH of an acid as it is neutralised?
What happens to the pH of an alkali as it is neutralised?
What are the two products formed in a neutralisation reaction?
Explain why indigestion tablets are taken to relieve indigestion.
If you were stung by a wasp what would you use to neutralise it?
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ACIDS AND METALS: Level E: Homework Sheet
Name
Glasgow 5-14 Science Programme Education Improvement Service 55
3
The table below shows how long it takes 1g of each of the five metals to react completely inhydrochloric acid.
Write down the metals in order of reactivity (most reactive first).
1
2
3
4
5
Which of these metals react most strongly with water?
The reactivity of calcium is mid-way between those sodium and magnesium. How long might 1g ofcalcium take to dissolve in the acid?
Explain why copper rather than magnesium is used to make water pipes.Concentrate on reactivity in your answer.
copper
iron
magnesium
sodium
zinc
years
600s
35s
15s
180s
METAL TIME
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ACIDS AND METALS: Level E: Homework Sheet
Name
Glasgow 5-14 Science Programme Education Improvement Service 56
4
As a homework exercise, pupils were asked to find the pH values of a number of substances found inthe home. One pupil wrote down her results as follows:
Make a table to show whether these substances were acid, alkali or neutral.
Draw and label a diagram to show how copper can be obtained from the electrolysis of copperchloride.
Name one neutral substance, one laboratory acid and one laboratory alkali.
ACIDS ALKALISNEUTRAL
lemon juice 3 washing up liquid 8 window cleaner 12
indigestion tablet 10
vinegar 4 bicarbonate of soda 9 salty water 7
coffee 5 cola drink 5sugar solution 7
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ACIDS AND METALS Level E: Glossary
Glasgow 5-14 Science Programme Education Improvement Service 57
Acids and MetalsGlossaryName
WORD MEANING
acid
alkali
neutralisation
pH scale
pH paper
Universal Indicator
solution
reaction
Reactivity Series
metals
displacement
electrolysis
electroplating
corrosion
extraction
electrode
ore
blast furnace
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ACIDS AND METALS Level E: Glossary
Glasgow 5-14 Science Programme Education Improvement Service 58
Acids and MetalsGlossaryName
WORD MEANING
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ACIDS AND METALS Level E: Pupil Checklist
Glasgow 5-14 Science Programme Education Improvement Service 59
Acids and MetalsPupil ChecklistName
By the end of this unit I should be able to:
Measure the pH of common solutions using pH paper and Universal Indicator.
State that acids have a pH value less than 7, neutral solutions have a pH value = 7 and alkalishave a pH value more than 7.
State that the lower the pH of an acid the greater the acidity; the higher the pH of an alkali thegreater the alkalinity.
State that acids and alkalis combine to form a neutral solution and adding acid lowers pH whileadding alkali raises pH.
State that when an acid neutralises an alkali, a salt and water is formed.
Give real life examples of neutralisation.
Plan and carry out a practical investigation on the differences in acid content in a range of softdrinks.
List metals in order of reactivity with oxygen, water and acid; potassium, sodium, calcium,magnesium, aluminium, zinc, iron, tin and copper.
Give examples of how reactivity relates to uses and sources of metals.
State that more reactive metals can displace less reactive metals from their solutions.
State that electrolysis can be used to obtain a metal from a solution.
Describe the effects of electroplating one metal with another using electrolysis.
Give examples of how some metals are extracted from their ores.
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ACIDS AND METALS Level E: Resources and Safety Issues
Glasgow 5-14 Science Programme Education Improvement Service 60
Acids and MetalsResources and Safety Issues
A list of the resources required for this topic is given. The list is intended to give an overall feel of the nature and quality of
the resources required. Teachers should refer to the resources column in the Topic Guide which gives a list of resources
(per pupil/group) for each activity. The pupil numbers in each group and the number of pupils in the class will determine
the number of items.
There are relatively few hazards associated with the science activities outlined in the Glasgow Science Programme. For
those that do exist, the risks they present are readily controlled. Areas of safety to be aware of are outlined in the following
section but more detailed advice on all aspects of safety in science can be found in Glasgow City Councils Science Code of
Practice SSF/S1, Hazardous Chemicals Manual COSHH/8b and Be Safe (GSF/25, SSF/S31).
Teachers should follow advice given in these documents as well as exercise common sense when carrying out science
activities. Pupils too, should be made aware of potential hazards and be encouraged to consider these when planning
their own investigations.
If there is any doubt about safety issues during the teaching of this topic, consult Technician Resource Service (TRS), 135
Westmuir Street, Glasgow G31 5EX, 0141 554 6322 (or David Lawson, Adviser in Science, 0141 287 4126).
Teachers must ensure that proper risk assessments are undertaken for each activity that is relevant to their own
establishment. The following advice is taken from Be Safe and is suitable generic risk assessment for all activities.
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ACIDS AND METALS Level E: Resources and Safety Issues
Glasgow 5-14 Science Programme Education Improvement Service 61
Acids and MetalsResources Universal Indicator paper with colour chart.
Universal indicator.
pH meter or probe with interface.
Variety of common solutions e.g. lemon, lime, orange and grapefruit juices, vinegar, citric acid, cream of tartar, coffee,
tea, deionised water, salt solution, Epsom salts, milk, milk of magnesia, washing up liquid, bicarbonate of soda, weak
ammonia solution.
Beakers (50 ml, 100ml 250ml).
Safety glasses.
Droppers and dimple tiles.
Text books, CD ROMs, internet access.
10 ml syringes marked with red and blue tape.
HCl, H2SO
4, CH
3CO
2H (ethanoic acid), NH
3OH, NaOH (all solutions are 0.1M).
Evaporating basin.
Bunsen burner, tripod stand, heat resistant mats.
Stirring rods.
Indigestion tablets/powder.
Lime for putting on soil.
Soft drinks various acidities.
Measuring cylinders.
Safety screen.
Samples of fresh and partially corroded magnesium, zinc, iron, tin, copper.
Tongs.
Samples of metals for reactions: potassium, sodium, calcium, magnesium, aluminium, zinc, iron, tin, copper.
Test tubes and racks.
Copper sulphate solution and nickel sulphate solution for displacement reactions.
Copper (II) chloride, carbon electrodes, power pack and leads for electrolysis.
Lead bromide (demonstration of molten electrolysis).
Steel nail for electroplating, crocodile clips.
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ACIDS AND METALS Level E: Resources and Safety Issues
Glasgow 5-14 Science Programme Education Improvement Service 62
Acids and MetalsSafety Issues(Advice taken from Be Safe)
ChemicalsThe substances suggested for use in this topic can be used safely by pupils with the correct precautions but remember that
any substance, even salt can be harmful if taken in sufficient quantity. Be aware that any substance in a fine powdery or
dusty form can be inhaled and thus harm health.
Safety code for using chemicals When transferring solid chemicals use small spoons kept for this purpose, and not fingers. For liquids, use droppers
always taking great care to avoid cross contaminating the chemicals.
Only dispense small quantities so that it is never necessary to return excess chemical to the container.
Prevent contact with the eyes. This can happen when chemicals spit out of a tube during heating or when fingers are
contaminated with chemicals. Wear safety goggles/spectacles for such activities.
Avoid skin contact and use protective gloves if the information on the substance indicates it is corrosive or irritating to
skin or is poisonous by skin absorption.
Wipe away any spillage at once.
Always wash hands after using chemicals.
It may be dangerous to mix chemicals. Even inadvertent mixing in a sink, etc. of household chemicals, such as bleach
with other cleaners or acid can produce a toxic gas. Warn children of the dangers.
Safety code for storing chemicals Always store chemicals in containers securely labelled with the name of the chemical, and with a hazard warning
symbol if appropriate. It is best to use the original containers.
Be aware of the risk of confusion and avoid using food or drinks containers for the storage of chemicals.
Keep only small quantities of chemicals.
Keep a record of all chemicals stored.
Store all chemicals in a locked cupboard or room away from heat sources and separate from those intended as foodstuffs.
Store flammable liquids separately from other chemicals. Where there is more than half a litre of any one flammable, it
must be locked in a flame-resistant cupboard or store.
Disposing of chemicalsConsult the Technician Resource Service (TRS), 135 Westmuir Street, Glasgow G31 5EX (or David Lawson, Adviser in Science
0141 287 4126) if you wish to dispose of any chemicals.
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ACIDS AND METALS Level E: Resources and Safety Issues
Glasgow 5-14 Science Programme Education Improvement Service 63
Particular advice for this topicChemicalsThere are a number of acids and alkalis suggested for this topic. The concentration of these solutions should not exceed
0.1 M. In all experiments, safe classroom practice should be carried out at all times.
The acids and alkalis used can be safely disposed of down the drain, flushing well with water.
Reference should be made to the COSHH guidelines in the school (or contacts see above) if there is any doubt about
disposal.
Some pointers to remember when dealing with the chemicals are: Prevent contact with the eyes this can happen if
fingers are contaminated. Wear safety goggles/spectacles for all activities, wipe away any spillage at once and always wash
hands after use.
MetalsWhen testing the more reactive metals (Alkali metals) this should be done as a teacher demonstration.
The Multi Media Science School on the schools network has some nice video clips of the more reactive metals which you
can show. It also has a nice but very short clip of the electrolysis of molten lead bromide which you could show.
When heating the magnesium ribbon remind the pupils not to look directly at the magnesium as it can damage their eyes,
a beaker of cold water could be used to drop the copper in to after heating it.
When collecting the hydrogen gas for testing remind the pupils not to touch the bottom of the test tubes containing the acid
and metal as they will be warm, in some cases very warm!
ElectrolysisWhen carrying out the electrolysis experiments remember to ventilate the room to prevent a build up of chlorine gas, and
do not exceed 6V on the power pack when doing the experiment.
ElectroplatingWhen carrying out the electroplating experiments remind the pupils to be careful with the electroplating solution and to
rinse it off immediately if they spill it on themselves. Remember to switch off the power packs before handling the electrodes.
Further informationConsult Technician Resource Service (TRS), 135 Westmuir Street, Glasgow G31 5EX, 0141 554 6322 (or David Lawson, Adviser
in Science, 0141 287 4126).