Download - Types of Chemical Change
Types of Chemical Change
http://mrged.flexinet.com.au
You already know about,1.The two main types of chemical bonding
2. Writing chemical formulas
(formulae)
This week we will find out about;1.Synthesis Reactions
2. Decomposition reactions
3. Single replacement reactions
4. Double replacement reactions
The Periodic Table
Types of chemical bonding. Revision
Ionic BondingThis type of bondingwill occur when a metal reacts with a non -metal
It always involves a complete transfer of electrons
It always produces IONS (charged particles)
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1 Na reacts with 1 Cl Formula = NaCl
Covalent BondingThis type of bondingwill occur when a non- metal reacts with a non -metal
Here both atoms will share electrons
It always produces molecules (particles with no charge)
In this section we will find out how to write chemical FORMULAE
Rules leading to correct formulaP
lease copy into your exercise books
1. Positive ions (cations) can join to negative ions (anions)
2. Positive ions usually form the first part of the name (99% cases)
3. If the formula is correct there is no overall charge
4. If you have more than one polyatomic ion it is placed inside brackets
Essential training ions
Positive ions(Cations)
Negative ions(Anions)
+ 1 - 1
+2 - 2
+3 - 3
sodium Napotassium K
hydrogen H
lithium Lisilver Ag
fluoride F chloride Clbromide Br hydroxide OH
nitrate NO3
hydrogencarbonate HCO3
magnesium Mgcalcium Ca
barium Bazinc Zniron(11) Fe
copper Cu
carbonate CO3oxide Osulphide S
sulphate SO4sulphite SO3
chromate CrO4
aluminium Al
chromium Cr
iron(111) Fe
nitride Nphosphate PO4
ammonium NH4
Chemical Formulae 1.
CHARGESIONS NUMBERS
FORMULA
sodium fluoride
NaF
Chemical Formulae 2.
CHARGESIONS NUMBERS
FORMULA
magnesium fluoride
Mg
F
Chemical Formulae 3.
CHARGESIONS NUMBERS
FORMULA
silver hydroxide
Ag
OH
Chemical Formulae 4.
CHARGESIONS NUMBERS
FORMULA
calcium nitrate
Ca
NO3
Chemical Formulae 5.
CHARGESIONS NUMBERS
FORMULA
ammonium carbonate
NH4
CO3
Chemical Formulae 6.
CHARGESIONS NUMBERS
FORMULA
aluminium bromide
Al
Br
Chemical Formulae 7.
CHARGESIONS NUMBERS
FORMULA
chromium sulphide
Cr
S
Chemical Formulae 8.
CHARGESIONS NUMBERS
FORMULA
BLANK ITEM
Try these:
1. lithium sulphite2. barium hydroxide3. copper carbonate4. hydrogen sulphide5. magnesium nitride6. ammonium bromide7. aluminium oxide.
In chemistry there are millions of chemical reactions. But most reactions can be classified as one of four types of reactions:
Synthesis: A + B -> ABDecomposition: AB -> A + B
Single Replacement: A + BC -> AC + BDouble Replacement: AB + CD -> AD + CB
Synthesis (Composition)
In a synthesis reaction (also known as a composition reaction), two substances combine to form a larger substance.
C O O+ CO O
Here are 3 synthesis reactions:
Hydrogen + oxygen yields water
2H2 + O2 -> 2H2O
Magnesium + nitrogen yields magnesium nitride
3Mg + N2 -> Mg3N2
Iron + sulphur yields iron(II) sulphide
Fe + S -> FeS
DecompositionIn a decomposition reaction, a larger substance
breaks apart and forms two or more simpler substances.
The first thing you may notice about a decomposition reaction is that it is the complete opposite of a synthesis reaction. In fact many synthesis reactions can be reversed into a decomposition reaction.
When you burn hydrogen gas, the hydrogen combines with oxygen to produce water.
2H2 + O2 -> 2H2O With an electrical current, water can be decomposed into hydrogen and oxygen gas.
2H2O -> 2H2 + O2
Some examples of decompositionHeat copper carbonate and it will decompose(Refer to flash animation .swf)
CuCO3 -> CuO + CO2
(Most carbonates decompose producing the oxide and carbon dioxide)
Heat lead(11) hydroxide and it will decompose
Pb(OH)2 -> PbO + H2O
FORMALUMBRO.MOV
THERMITE.MOV
REDUCTIONCUO.MOV
FormWater.MOV
NitrogTriiodide.MOV
PrecipitaReact.MOV
6x Quicktime mov files
1. Watch all 12 mov files (available on SET drive)
2. Classify each as either, synthesis, decompostion, single of double replacement reactions
3. Write a correct chemical equation for each!Some may require some research
TRY THESE:
Single Replacement
In a single replacement reaction, a more active element replaces a less active element in a compound.
more reactive less reactive
Single Replacement
Here Mg is more reactive than Pb
Single Replacement
No surprise! fluorine is more reactive than chlorine
If fluorine gas is bubbled through a solution of potassium chloride, the fluorine will replace the chlorine.
2KCl + F --> 2KF + Cl
This reaction can be represented as follows;
Please note this PPT may be updated over the weekend
Mr G