preparation • over 300 recipes of commonmolarity the most common unit of solution concentration is...

MolarityThe most common unit of solution concentration is molarity (M). The molarity of a solution is defined as the number of moles of solute per one liter of solution. Note that the unit of volume for molarity is liters, not milliliters or some other unit. Also note that one liter of solution contains both the solute and the solvent. Molarity, therefore, is a ratio between moles of solute and liters of solution. To prepare laboratory solutions, usually a given volume and molarity are required. To determine molarity, the formula weight or molar mass of the solute is needed. The following examples illustrate the calculations for preparing solutions.

If starting with a solid, use the following procedure:

• Determinethemassingramsofonemoleofsolute,themolarmass, MMs.

• Decidevolumeofsolutionrequired,inliters,V.

• Decidemolarityofsolutionrequired,M.

• Calculategramsofsolute(gs) required using equation 1. eq. 1. gs = MMs x M xV

• Example:Prepare800mLof2Msodiumchloride. (MMNaCl=58.45g/mol) gNaCl=58.45g/molx2mol/Lx0.8L gNaCl=93.52gNaCl

Dissolve93.52gofNaClinabout400mLofdistilledwater,thenaddmorewateruntilfinalvolumeis800mL.

If starting with a solution or liquid reagent:

• Whendilutingmoreconcentratedsolutions,decidewhatvolume(V2)andmolarity(M2) the final solution should be. Volumecanbeexpressedinlitersormilliliters.

Basic Concepts of Preparing Solutions

Many of the reagents used in science are in the form of solutions which need to be purchased or prepared. For many purposes, the exact value of concentration is not critical; in other cases, the concentration of the solution and its method of preparation must be as accurate as possible.TheFlinnLaboratorySolutionPreparationreferencesectionis designed for both the novice and experienced solution maker. It provides valuable information on the basic concepts of preparing solutions and instructions for preparing most solutions required in the high schoolsciencelaboratory.Professionalqualitysolutionsarepossiblewhen high quality and fresh chemicals and solvents are used, and meticulous procedures are followed. Many of the solutions described

•Basicconceptsofpreparingsolutions

•Over300recipesofcommonlaboratorysolutions

•Solutionpreparationtips

LaboratorySolutionPreparation

inthissectionareavailableready-madefromFlinnScientifictosavevaluable laboratory prep time.

The section is divided into several parts for your convenience.

Basic concepts of preparing solutions

Preparationofsimpleinorganicsaltsolutions

Preparationsofacidandbasesolutions

RecipesforBiological,Histological,andChemicalsolutions

• Determinemolarity(M1) of starting, more concentrated solution.

• Calculatevolumeofstartingsolution(V1) required using equation2.Note:V1mustbeinthesameunitsasV2. eq.2.M1V1 = M2V2

• Example:Prepare100mLof1.0Mhydrochloricacidfromconcentrated(12.1M)hydrochloricacid. M1V1 = M2V2 (12.1M)(V1)=(1.0M)(100mL) V1=8.26mLconc.HCl

Add8.26mLofconcentratedHCltoabout50mLofdistilledwater,stir,thenaddwaterupto100mL.

PercentSolutionsMass percent solutions are defined based on the grams of solute per100gramsofsolution.

Example:20gofsodiumchloridein100gofsolutionisa20%by mass solution.

Volume percent solutions are defined as milliliters of solute per 100mLofsolution.

Example:10mLofethylalcoholplus90mLofH2O(makingapprox.100mLofsolution)isa10%byvolume solution.

Mass-volume percent solutions are also very common. These solutionsareindicatedbyw/v%andaredefinedasthegramsofsoluteper100millilitersofsolution.

Example:1gofphenolphthaleinin100mLof95%ethyl alcoholisa1w/v%solution.

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BASIC CONCEPTS OF PREPARING SOLUTIONS continued on next page.

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ConversionBetweenPercentSolutionsYou may wish to convert mass percent to volume percent or vice versa. If so, follow this procedure:

A10%bymasssolutionofethylalcoholinwatercontains10gofethylalcoholand90gofwater.

1. The formula for determining the volume of the component (ethylalcoholinourexample)is:

mass of ethyl alcohol Volume =—————————— density of ethyl alcohol

2.Determinethevolumeofthetotalsolutionbydividingthemass of the solution by the density of the solution.

3.Determinethepercentbyvolumebydividingthevolumeofthe component by the volume of the solution.

Let’ssolve1,2,and3aboveasfollows:

1.Massofethylalcohol=10g(given)

Densityofethylalcohol=0.794g/mL(fromhandbook)

mass Volume = ——— density 10g Volumeofethylalcohol = —————= 12.6mL 0.794g/mL

2.Massofsolution=100g(given)

Densityofsolution(10%ethylalcohol)=0.983g/mL (from handbook)

100g Volumeofsolution = —————=101.8mL* 0.983g/mL

3.Volumepercentofsolution

volumeofethylalcohol 12.6 Percent = —————————— =——— =12.4% totalvolumeofsolution 101.8

Reverse the procedure to convert volume percent to mass percent.

* The volume percent statement generally is accurate but the volume percent is not always calculated directly from the volumes of the mixed ingredients because the final volume may not equal the sum of the separate volumes. In our solution (No. 2 above) note that if the alcohol volume (12.6 mL) is added to the water volume (90 mL), the final volume is less than 102.6 mL.

Basic Concepts of Preparing Solutions,continued

CalculatingMolarityfromPercentSolutionsTo determine the molarity of a mass percent solution, the density of the solution is required. Use the following procedure:

1.Determinethemassofsolutionbymultiplyingthevolumeofthe solution by the density of the solution.

mass = volume x density

2.Determineconcentrationinpercentbymassofthesoluteinsolution. Change to the decimal equivalent.

3.Calculatethemolarmassofthecompound,MM.

4.Multiplymass(step1)bymass%(step2)anddividebymolecularmass(step3)tofindthenumberofmolespresentinthe whole solution.

5.Dividethenumberofmoles(step4)bythevolumeinlitersofthe solution to find the molarity of the solution.

Example:Determinemolarityof37.2%hydrochloricacid(density1.19g/mL).

1.Massofsolution=1,000mLx1.19g/mL=1,190g

2.Mass%=37.2%=0.372

3.Molarmassofhydrochloricacid=36.4g/mol

4. massxmass% 1,190gx0.372 ———————— =———————— =12.1moles MMHCl 36.4g/mol

5.Molarity=moles/liters=12.1moles/1liter=12.1M

Definitions

Buffer: A solution which tends to maintain a constant pH when excess acid or base is added.

Concentrated: For some commonly used acids and bases, the maximumsolubility(atroomtemperature)inanaqueoussolutionor as a pure liquid.

Concentration: The relative amount of solute and solvent in a solution.

Hydrates: Compoundscontainingwaterchemicallycombinedinadefiniteratio.Computationsusingformulaweightmusttakethewater molecules into account.

Miscible: The ability of two liquids to be completely soluble in one another.

Molality: A concentration unit (m); defined as the number ofmoles of solute divided by the number of kilograms of solvent.

Molar Mass: The mass of a mole of any element or compound.

Molarity:A concentration unit (M); defined as the number ofmoles of solute divided by liters of solution.

“Your Safer Source for Science Supplies”

Name / Formula / F.W. Concentration g/L

Aluminum chloride 0.2M 48.3g AlCl3•6H2O 0.05M 12.1g 241.43

Aluminum nitrate 0.1M 37.5g Al(NO3)3•9H2O 375.13

Aluminum sulfate 0.1M 66.6g Al2(SO4)3•18H2O 666.42

Ammonium acetate 1.0M 77.1g NH4C2H3O2 0.1M 7.7g 77.08

Ammonium chloride 1.0M 53.5g NH4Cl 0.5M 26.7g 53.49

Ammonium nitrate 1.0M 80.0g NH4NO3 0.5M 40.0g 80.04 0.1M 8.0g

Ammonium sulfate 0.1M 13.2g (NH4)2SO4 132.1

Barium chloride 0.1M 24.4g BaCl2•2H2O 244.28

Barium hydroxide 0.1M 31.5g Ba(OH)2•8H2O 315.50

Barium nitrate 0.5M 130.7g Ba(NO3)2 0.1M 26.1g 261.35

Bismuth nitrate 0.1M 48.5gin Bi(NO3)3•5H2O 500mL6M 485.1 HNO3*

Preparation of Simple Inorganic Salt Solutions

PREPARATION OF SIMPLE INORGANIC SALT SOLUTIONS continued on next page.


Bismuth trichloride 0.2M 63.1gin BiCl3 500mL3M 315.34 HCl*

Cadmium chloride 0.1M 22.8g CdCl2•21⁄2H2O 228.34

Cadmium nitrate 0.1M 30.8g Cd(NO3)2•4H2O 308.49

Calcium acetate 0.5M 88.1g Ca(C2H3O2)2•H2O 0.1M 17.6g 176.19

Calcium chloride 1.0M 147.0g CaCl2•2H2O 0.1M 14.7g 147.02

Calcium hydroxide saturated 2g† Ca(OH)2 74.10

Calcium nitrate 0.5M 118.1g Ca(NO3)2•4H2O 0.1M 23.6g 236.16

Chromium(III) chloride 0.1M 26.6g CrCl3•6H2O 266.48

Chromium(III) nitrate 0.1M 40.0g Cr(NO3)3•9H2O 400.18

Cobalt(II) chloride 0.1M 23.8g CoCl2•6H2O 237.95

Cobalt(II) nitrate 0.1M 29.1g Co(NO3)2•6H2O 291.05

Copper(II) chloride 0.5M 85.2g CuCl2•2H2O 0.1M 17.0g 170.49

Copper(II) nitrate 0.5M 120.8g Cu(NO3)2•3H2O 0.1M 24.2g 241.6

Copper(II) sulfate 1.0M 249.7g CuSO4•5H2O 0.5M 124.8g 249.69

Iron(II) sulfate 0.01M 2.8gand FeSO4•7H2O 1mLconc. 278.03 H2SO4*

Iron(III) chloride 1.0M 270.3g FeCl3•6H2O 0.1M 27.0g 270.32

Iron(III) nitrate 0.1M 40.4g Fe(NO3)3•9H2O 404.00

* Add solid to acid solution, stir, then add to water. Dilute to 1 L. Remember, always add acid to water.

†Approximate amount for 1 L of saturated solution. Keep adding solute until it no longer dissolves; stir for 1 hour, then filter.

Normality:Aconcentrationunit (N);definedas thenumberofequivalents of solute per liter of solution. (e.g., 1 M H2SO4 = 2NH2SO4)

Saturated Solution: A solution that contains the maxi mum amount of a particular solute that will dissolve at that temperature.

Solute: The substance which is dissolved, or has gone into solution (typicallyasolid).

Solution: A uniform homogeneous mixture of two or more substances. The individual substances may be present in varying amounts.

Solvent: The substance which does the dissolving (typically aliquid,suchaswateroralcohol).Mustbegreaterthan50%ofthesolution.

Standard Solution: A very precise solution, usually to 3–4significant figures, used in quantitative analysis or an analytical procedure.

Supersaturated Solution: A solution that contains more solute than equilibrium conditions allow; it is unstable and the solute may precipitate upon slight agitation or addition of a single crystal.




Safety Reference

1.Weighsolid.

3. Transfer solid, wash out weighing dish.

4.Stiruntildissolved. Add more water if necessary.

5. Add deionized or distilled water up to mark.


Lead acetate 0.1M 38.0g Pb(C2H3O2)2•3H2O 379.34

Lead chloride saturated 12.0g† PbCl2 278.12

Lead nitrate 1M 331.2g§ Pb(NO3)2 0.5M 165.6g 331.2 0.1M 33.1g

Lithium carbonate 0.1M 7.4g Li2CO3 73.89

Lithium chloride 1.0M 42.4g LiCl 0.1M 4.2g 42.40

Lithium nitrate 1.0M 69.0g LiNO3 0.5M 34.5g 68.95

Magnesium bromide 0.1M 29.2g MgBr2•6H2O 292.25

Magnesium chloride 1.0M 203.3g MgCl2•6H2O 0.1M 20.3g 203.33

Magnesium hydroxide saturated 300g† Mg(OH)2 58.34

Magnesium nitrate 0.1M 25.6g Mg(NO3)2•6H2O 256.43

Magnesium sulfate 0.5M 123.3g MgSO4•7H2O 0.1M 24.7g 246.50

Manganese chloride 0.5M 99.0g MnCl2•4H2O 0.1M 19.8g 197.91

Preparation of Simple Inorganic Salt Solutions,continued



Manganese sulfate 0.2M 33.8g MnSO4•H2O 0.1M 16.9g 169.01

Mercury(II) chloride 0.25M 67.9g HgCl2 0.10M 27.2g 271.50

Mercury(II) nitrate 0.1M 34.2gin Hg(NO3)2•H2O 50mLconc. 342.63 HNO3*

Mercury(I) nitrate 0.1M 56.2gin Hg2(NO3)2•2H2O 100mLconc. 561.22 HNO3*

Mercury(I) sulfate 0.1M 49.7gin Hg2SO4 30mL1M 497.24 HNO3*

Nickel chloride 0.25M 59.4g NiCl2•6H2O 0.1M 23.8g 237.72

Nickel nitrate 1M 290.8g Ni(NO3)2•6H2O 0.2M 58.2g 290.82

Nickel sulfate 1.0M 262.9g NiSO4•6H2O 0.5M 131.4g 262.87

Potassium bromide 0.5M 59.5g KBr 0.1M 11.9g 119.02

Potassium carbonate 0.5M 69.1g K2CO3 0.1M 13.8g 138.21

Potassium chloride 0.5M 37.3g KCl 0.1M 7.5g 74.56


†Approximate amount for 1 L of saturated solution. Keep adding solute until it no longer dissolves; stir for 1 hour, then filter.

§ Use 7.5 mL conc. HNO3 to help dissolve.

MakeaSolution

2. Fill volu metric flask 1⁄3–1⁄2 full with deionized or distilled water.




Potassium chromate 1.0M 194.2g K2CrO4 0.5M 97.1g 194.21 0.1M 19.4g

Potassium dichromate 0.1M 29.4g K2Cr2O7 294.22

Potassium ferricyanide 0.5M 164.6g K3Fe(CN)6 0.1M 32.9g 329.26

Potassium ferrocyanide 0.1M 42.2g K4Fe(CN)6•3H2O 422.41

Potassium hydrogen 0.1M 20.4g phthalate KHC8H4O4 204.23

Potassium hydroxideseepage118

Potassium iodate saturated 214.0g† KIO3 0.2M 42.8g 214.01 0.1M 21.4g

Potassium iodide 1M 166.0g Kl 0.5M 83.0g 166.01 0.2M 33.2g

Potassium nitrate 0.5M 50.6g KNO3 0.1M 10.1g 101.11

Potassium permanganate 0.2M 31.6g KMnO4 0.1M 15.8g 158.04 0.01M 1.6g

Potassium phosphate, 0.1M 13.6g monobasic KH2PO4 136.09

Potassium phosphate, 0.1M 17.4g dibasic K2HPO4 174.18




Potassium phosphate, 0.1M 21.2g tribasic K3PO4 212.27

Potassium sulfate 0.5M 87.1g K2SO4 0.1M 17.4g 174.27

Potassium thiocyanate 1.0M 97.2g KSCN 0.5M 48.6g 97.18 0.1M 9.7g

Silver nitrate 0.5M 84.9g AgNO3 0.1M 17.0g 169.87

Sodium acetate 1M 136.1g NaC2H3O2•3H2O 0.5M 68.0g 136.08

Sodium bicarbonate 0.5M 42.0g NaHCO3 0.1M 8.4g 84.01

Sodium borate 4% 40.0g Na2B4O7•10H2O 381.42

Sodium bromide 1.0M 102.9g NaBr 0.1M 10.3g 102.90

Sodium carbonate saturated 214.0g† Na2CO3 1.0M 106.0g 105.99 0.1M 10.6g

Sodium carbonate 1.0M 124.0g Na2CO3•H2O 0.1M 12.4g 124.00


† Approximate amount for 1 L of saturated solution. Keep adding solute until it no longer dissolves; stir for 1 hour, then filter.

Nitrates(NO3–): All nitrates are soluble.

Acetates (C2H3O2–): All acetates are soluble; silver acetate is

moderately soluble.

Bromides(Br–) Chlorides(Cl–) and Iodides(I–): Most are soluble except for salts containing silver, lead, and mercury.

Sulfates(SO42–): All sulfates are soluble except barium and lead. Silver,mercury(I),andcalciumareslightlysoluble.

Hydrogen sulfates (HSO4–) :Thehydrogen sulfates (akabisul

fates) are more soluble than the sulfates.

Carbonates (CO32–), phosphates (PO43–), chromates (CrO42–), silicates (SiO42–): All carbonates, phosphates, chromates, and silicates are insoluble, except those of sodium, potassium, and ammonium.AnexceptionisMgCrO4, which is soluble.

GeneralSolubilityRulesforInorganicCompounds

Hydroxides (OH–):Allhydroxides(exceptlithium,sodium,potassium,cesium,rubidium,andammonium)areinsoluble;Ba(OH)2, Ca(OH)2andSr(OH)2 are slightly soluble.

Sulfides (S2–): All sulfides (except sodium, potassium, ammonium, magnesium, calcium and barium) are insoluble. Aluminum and chromium sulfides are hydrolyzed and precipitate as hydroxides.

Sodium (Na+), potassium (K+), ammonium (NH4+): All sodium,

potassium,andammoniumsaltsaresoluble.(Exceptsometransition metal compounds.)

Silver (Ag+):Allsilversaltsareinsoluble.Exceptions:AgNO3 and AgClO4;AgC2H3O2 and Ag2SO4 are moderately soluble.




Safety Reference


Sodium chloride saturated 390.0g† NaCl 1.0M 58.5g 58.45 0.1M 5.8g

Sodium dichromate 0.1M 29.8g Na2Cr2O7•2H2O 298.03

Sodium fluoride 0.1M 4.2g NaF 41.99

Sodium hydroxideseepage1156

Sodium iodide 0.5M 75.0g NaI 0.1M 15.0g 149.92

Sodium nitrate 0.5M 43.0g NaNO3 0.1M 8.5g 84.99

Sodium oxalate 0.1M 13.4g Na2C2O4 134.00

Sodium phosphate, 0.1M 13.8g monobasic NaH2PO4•H2O 137.99

Sodium phosphate, 0.5M 134.0g dibasic 0.1M 26.8g Na2HPO4•7H2O 268.07

Sodium phosphate, 0.5M 71.0g dibasic 0.1M 14.2g Na2HPO4 141.96

Sodium phosphate, 0.1M 38.0g tribasic Na3PO4•12H2O 380.12

Sodium sulfate saturated 600g† Na2SO4•10H2O 1.0M 322.2g 322.19 0.5M 161.1g



Sodium sulfate saturated* 260g† Na2SO4 1.0M 142.0g 142.02 0.5M 71.0g

Sodium sulfide 2.0M 48.0g§ Na2S•9H2O 1.0M 24.0g 240.18

Sodium sulfite 1.0M 126.1g Na2SO3 126.05

Sodium thiosulfate 0.5M 124.1g Na2S2O3•5H2O 0.1M 24.8g 248.19

Strontium chloride 0.5M 133.3g SrCl2•6H2O 0.1M 26.7g 266.64

Strontium hydroxide saturated 220g† Sr(OH)2•8H2O 266.82

Strontium nitrate 1.0M 211.6g Sr(NO3)2 0.5M 105.8g 211.63

Tin(II) chloride 0.1M 22.6gin SnCl2•2H2O 1MHCl* 225.65

Tin(IV) chloride 0.1M 35.1gin SnCl4•5H2O 3MHCl* 350.61

Zinc chloride 0.5M 68.1gandZnCl2 1mL12M 136.29 HCl* 0.1M 13.6g

Zinc nitrate 0.5M 149.7g Zn(NO3)2•6H2O 0.1M 29.7g 297.49

Zinc sulfate 1.0M 287.6g ZnSO4•7H2O 0.1M 28.8g 287.56

* Add solid to acid solution, stir, then dilute to 1 L. Remember, always add acid to water.

† Approximate amount for 1 L of saturated solution. Keep adding solute until it no longer dissolves; stir for 1 hour, then filter.

§ Use hot water, stir vigorously.

DistilledorDeionizedWater—WhichDoINeed?

Distilled water is free of inorganic materials, suspendedimpurities, and most organic contaminants. To make or buydistilledwaterisexpensive.Whiletheremaybeschoollaboratory applications where distilled water is required, in manyapplications,deionized(akademineralized)waterwilldojustaswell.Deionizedwater,likedistilledwater,isfreeof inorganic materials and most suspended con taminants. If you need organicfree water, buy a still or buy distilled water.

IncreasetheRateofDissolvingSolids

A solvent will only dissolve a limited quantity of solute at a definite temperature. However, the rate at which the solute dissolves can be accelerated by the following methods:1.Pulverizeorgrindupthesolidtoincreasethesurfacearea

of the solid in contact with the liquid.2.Heat thesolvent.Thiswill increase therateofsolution

because the molecules of both the solvent and the solute move faster.

3.Stirvigorously.Combinations of all three methods, when practical, willdissolve solids more quickly.



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Name / Formula / F.W. Concentration Amount/Liter§

Acetic Acid* 6M 345mL CH3CO2H 3M 173 F.W.60.05 1M 58 99.7%,17.4M 0.5M 29 sp.gr.1.05 0.1M 5.8

Hydrochloric Acid* 6M 500mL HCl 3M 250 F.W.36.4 1M 83 37.2%,12.1M 0.5M 41 sp.gr.1.19 0.1M 8.3

Nitric Acid* 6M 380mL HNO3 3M 190 F.W.63.01 1M 63 70.0%,15.8M 0.5M 32 sp.gr.1.42 0.1M 6.3

Phosphoric Acid* 6M 405mL H3PO4 3M 203 F.W.98.00 1M 68 85.5%,14.8M 0.5M 34 sp.gr.1.70 0.1M 6.8

Sulfuric Acid* 9M 500mL† H2SO4 6M 333† F.W.98.08 3M 167† 96.0%,18.0M 1M 56 sp.gr.1.84 0.5M 28 0.1M 5.6

* Always add acid to water. The addition of acid to water is an exothermic reaction. Use high temperature (e.g., Pyrex®) glassware.

†Extremely exothermic, submerge mixing vessel in an ice bath. See adjacent box.

§ The amount of solute required to prepare one liter of solution.

Preparation of Acid Solutions

PreparingSulfuricAcidSolution?Always ADD ACID (AA) to water! A great amount of heat is liberated when sulfuric acid is added to water. The temperature of the solution will rise rapidly. In fact, the temperature may rise so fast that the solution will boil and possibly spatter a strongly acidic solution. Considerimmersing your mixing vessel in a bucket of ice to control the solution temperature. Always add the acid to water very slowly while stirring continuously.

Many science teachers spend too much time and energy complying with regulations concerning the use,storage,andhandlingoflaboratorychemicals.FlinnScientific’suniquechemicalpackagingandlabeling meet or exceed these regulations, allowing you more time to do what you do best…teach science!DependonFlinnScientifictofulfillallofyourchemicalneeds.

Preparation of Acid Solutions



Safety Reference

Entirely constructed of 1" thick,

high density, 9-ply plywood

and finished with Super

Chem-Tuff® Paint.

All polypropylene, .125'' thick.

Top recessed to include a liquid-tight polypropy-l ene tray. Tray will hold 12 liters of spilled liquid. Use this top tray as a dispensing area.

Interlocking wooden door

assembly.

Optional polypropylene compartment to accommodate

nitric acid is available.

One fixed-position shelf

included.

Cabinet floor constructed with a 2'' high liquid-tight trough to contain spillage and provide secondary containment.

FlinnAcidCabinets• Woodenacidcabinetsaresaferandmoredurable

thanmetalcabinets.

• AcidattacksALLmetalcabinets.

• NometalisusedanywhereintheinteriorconstructionofFlinn/SciMatCoacidcabinets.

Preparation of Base Solutions

PreparingSodiumHydroxideSolution?A great amount of heat is liberated when sodium hydroxide and water are mixed. The temperature of the solution may rise very rapidly. In fact, the temperature may rise so fast that the solution may boil and possibly spatter a hot, caustic solution. Immerse the flask or beaker in an ice–water bath to control the solution temperature. In addition, pay special attention to the condition of the beaker or flask, you use to prepare these solutions. If you use a glass vessel it must be borosilicate glass and it must be free of any scratches, chips or breaks. Inspect the vessel carefully before use. Add ingredients slowly with continuous stirring.

Name / Formula / F.W. Concentration Amount/Liter§

Ammonium Hydroxide* 6M 405mL NH4OH 3M 203 F.W.35.05 1M 68 0.5M 34 0.1M 6.8

Potassium Hydroxide 6M 337g KOH 3M 168 F.W.56.11 1M 56 0.5M 28 0.1M 5.6

Sodium Hydroxide† 6M 240g NaOH 3M 120 F.W.40.00 1M 40 0.5M 20 0.1M 4.0

* Use concentrated (14.8 M) ammonium hydroxide.

†Exothermic reaction. Use high temperature (borosilicate) glassware.

§ The amount of solute required to prepare one liter of solution.

SafeStorageofAcidsFlinn/SciMatCo Wooden Acid Cabinets are Ideal for School StoreroomsCorrosive chemicals, such as strong acids andbases, must be isolated from other chemicals to prevent accidental contact and hazardous reaction conditions. The best way to isolate your corrosive chemicals is to store them in an approved corrosive storage cabinet like the Flinn wooden acid cabinet. Locked storage cabinets also providesecurity against theft and vandalism.

Flinn wood acid cabinets are designed specifically for high school chemical storerooms. Made from nineply, highdensity plywood, Flinn acid cabinets are guaranteed never to rust or corrode.

Flinn acid cabinets will provide long life and safe, secure storage for all your corrosives.Seepages1062–1066formoreinformation.

Catalog No. Description Price/Each

SE8041 Flinn Acid Cabinet; Wood; interior PARTIALLY lined with poly propylene (floor, shelf and top tray)

$696.75*

SE8051 Flinn Acid Cabinet; Wood; interior COMPLETELY lined with polypropylene (floor, interior walls, interior top and top tray)

930.00*

* Cabinet must be shipped by motor truck freight.© 2011 Flinn Scientific, Inc. All Rights Reserved.


• Donotusechemicalsfromunlabeledcontainers.

• Donotplacelabelsontopofoneanother.

• Labelchemicalsclearlyandpermanently.

Anunlabeledcontainerwillbecometomorrow’s“MysterySubstance.”Agreasepencilorlabelcanhelpeliminateafutureproblem and a lot of expense.

You Make It—You Label It!Minimum label requirements:

1. Identity of contents

2.Concentration

3. Your name

4

4.Dateofpreparation(ifapplicable)

5.Hazardalert(ifapplicable)

BecomeaLabelFanatic!Safety Tip

Aceto-Carmine (Schneider)Place0.5gofcarmineand55mLofDIwater ina200-mLflask,bring toaboil,andadd45mLofglacialaceticacid.Plugflask with cotton wool, boil again, cool and filter. (stain and fixative, good forprotozoa and nuclei)

Aceto-Orcein Staining SolutionHeat 31.5 mL of glacial acetic acid and13.5 mL of DI water almost to boiling.When acid is hot, add 2 g of syntheticorceinandallowtocool.Dilutebyadding55mLofDIwater;stirandfilter.(connective tissue stain)

Adrenaline HydrochlorideDissolve0.1gofadrenalinehydrochloridein100mLofRinger’ssolution.

Adipoyl Chloride/Hexane SolutionDissolve 4.6 g of adipoyl chloride inapproximately50mLofhexane,stir,thendilute to 100 mL with hexane. (nylondemonstration)

Agar (Non-nutrient)Suspend15gofagarin1LofDIwater.Heat to a boil and stir until completely dissolved.Letcoolto50–55°Candthendispense into desired containers. Agar will firm as it cools. Must add a nutrient if using for culture growth.

Agarose GelThe standard concentration of agarose in the gel is 0.8%—a concentration thatoffers a compromise between band resolution and running time. The following directions are for 100-mL of an 0.8%agarose solution. Stir 0.8 g of agaroseinto 100 mL of working strength (1X)electrophoresisbuffer(TBEorTAE)inaglassErlenmeyerflask.Stopperwithnon-absorbent cotton,or foamplug.Dissolveagarosebyheatinginamicrowave(30–40

Recipes for Biological, Histological, and Chemical Solutions

seconds, stir, repeat) or on a hot plate. Heat until solution is clear and agarose appears to be fullydissolved.Stir frequently anddo not allow solution to boil for more than a few seconds. Prepare the casting tray,place thewell comb,andpour thegel(s)when the agarose solution has cooled to approximately 60 °C.Allow the gel tofullysolidifyonaflat,levelsurfacefor20to30minutes.Gelshouldbeopaqueandfirm to the touch.

See pages 828–829 for a complete listing of culture media.

Alizarin0.1% methanol solution: Dissolve 0.1gofalizarinin50mLofmethylalcohol, then dilute to 100 mL with methylalcohol.(pHindicator)

Alizarin Red S1%aqueous:Dissolve1gofalizarinredSin50mLofDIwater,thendiluteto100mL.(pHindicator)

Alizarin Yellow R0.1%aqueous:Dissolve0.1gofalizarinyellowRin50mLofDIwater,thendiluteto100mL.(pHindicator)

AluminonDissolve0.1gofaurintricarboxylicacidin100mLofDIwater.(qualitativereagentfor aluminum)

Amylase0.5%aqueous:Dissolve0.5gofamylasein50mLofDIwater, thendilute to100mL.Preparefresh.(starchdigestion)

Aniline Blue Alcohol Stain1%alcohol:Dissolve1gofanilinebluein 100 mL 85% ethyl alcohol. (stain forcellulose)

Aniline Blue Aqueous Stain

0.5%aqueous:Dissolve0.5ganilinebluein50mLDIwater,thendiluteto100mL.Filter if necessary. (stain for algae andfungi)

Aniline Blue Indicator

0.1%aqueous:Dissolve0.1ganilinebluein50mLDIwater,thendiluteto100mL.(pHindicator)

Baker’s Softening Fluid

Mix 10 mL of glycerol, 54 mL of 95%ethanoland35mLDIwater.(softeningofanimal structures)

Barfoed’s Reagent

Add 10 mL of glacial acetic acid to 1 L of DI water and stir.Add 66.5 g ofcupric acetate monohydrate. Heat and stir until solid is completely dissolved. (testfor glucose)

Benedict’s Qualitative Solution

Dissolve173gofsodiumcitratedihydrateand 100 g sodium carbonate anhydrousin800mLDIwater.Warmandstirtoaiddissolution. Filter if necessary. In a separatecontainer,dissolve17.3gcopper(II)sulfatepentahydratein100mLDIwater.Slowly,while stirringconstantly,add thecopper sulfate solution to the first solution. Letcoolanddiluteto1LwithDIwater.(testforthepresenceofsimplesugars)

RECIPES continued on next page.

Note: DI water denotes either distilled or deionized water.

Recipes for Laboratory Solutions



Safety Reference

Benedict’s Quantitative SolutionDissolve 18.0 g of copper (II) sulfatepentahydrate in100mLofDIwaterandset aside. Dissolve 100.0 g of sodiumcarbonate anhydrous, 200.0 g of sodiumcitratedihydrate,and125gofpotassiumthiocyanate in800mLDIwater.Heat, ifnecessary to aid dissolution of the solids. Allow the solution to cool, then transfer to a 1-L volumetric flask. Slowly, whilestirring constantly, add the copper sulfate solution to the 1-L flask. Prepare a 0.1M potassium ferrocyanide solution by dissolving 0.25 g of potassium ferrocyanidetrihydratein5mLofDIwater.Addtothe1-Lvolumetricflask,stir,thendiluteto1LwithDIwater.Filter ifnecessary.(25mLof thissolution is reducedby50mg of glucose)

Bial’s Reagent (Sumner)Add 4 drops of 10% iron(III) chloridesolution to 100mLof 6Mhydrochloricacid.Add.03goforcinolandstir.(testforpentoses and glycuronic acids)

Bile Salts 5%aqueous:Dissolve5gofbilesaltsin50mLofDIwater,diluteto100mL.Mixgentlytoavoidfoam.(digestivestudies)

Bismark Brown Y0.5%aqueous:Dissolve0.5gofbismarkbrownYin50mLofDIwater,dilute to100mL,stir,andfilterifnecessary.(stainfor protozoa)

Biuret SolutionDissolve2.3gofcopper(II)sulfatepentahydratein230mLofDIwater.Setaside.Dissolve308gsodiumhydroxide in770mL of DI water (very exothermic; cool

Recipes for Biological, Histological, and Chemical Solutions,continued

vessel in an ice water bath) and cool to room temperature. Add all the copper sulfate solution to the sodium hydroxide solution.Solutionshouldbeblue.(testforproteins)

Blood Agar Base InfusionSuspend40gofbloodagarbaseinfusionin1LofDIwater.Heattoaboilwhilestirringvigorously.Boil foroneminute.Sterilizefor15minat121°C(15lbs.ofpressure)inanautoclaveorpressurecooker.Coolto50–55°Candpour into sterilizedculturedishes.(culturemedium)

BoraxAdd4gBorax (sodiumborate,Na2B4O7 • 10H2O) to 100 mL of DI water. Stir.(preparationofslime)

Borax CarmineDissolve2gofborax (akasodiumtetraborate)in50mLofDIwater,add1.5gofcarmineandboilfor30minutes.Letcool,makeupto50mLwithDIwater,thenadd50mLof70%ethylalcohol.Letstandforafewdays,thenfilter.(goodgeneralstainfor plant and animal tissue)

Borax Methylene BlueHeat100mLofDIwaterto60°Candstirin2gmethyleneblueand5gborax.Allowtocoolslowly.Solutionimproveswithage.(connectivetissuestain,Negribodies)

Bouin’s FixativeMixtogether75mLofsaturatedaqueouspicricacidsolution,25mLofcommercialformalin (10% formaldehyde solution),and5mLofglacialaceticacid.(plantandanimal tissue fixative)

Brilliant Blue R-250

Dissolve 0.25 g of Coomassie brilliantblue R-250 in 40 mL methyl alcohol.Add40mLDIwater,then7mLconcentrated acetic acid. Dilute to 100 mL with DI water. (staining proteins in polyacrylamide and agarose gels for electrophoresis)

Brilliant Blue G-250

Dissolve0.1gofCoomassiebrilliantblueG-250 in 25 mL methyl alcohol.Add40 mL DI water, then 5 mL acetic acid.Diluteto100mLwithDIwater.(stainingproteins in polyacrylamide and agarose gels for electrophoresis)

Brilliant Cresyl Blue

Dissolve0.85gsodiumchloridein75mLofDIwater.Add1gbrilliantcresylblueandstirtodissolve.Diluteto100mLwithDI water. (vital stain, general stain forprotozoa and plant cells)

Brilliant Green

1% aqueous: Dissolve 1 g of brilliantgreenin50mLofDIwater,diluteto100mL,stir,andfilterifnecessary.(stainforplant cytoplasm, and pH indicator)

Bristol’s Solution

Dissolve 1 g of potassium dihydrogenphosphate, 1 g sodium nitrate, 0.3 g ofmagnesium sulfate, 0.1 g calcium chloride,0.1gsodiumchlorideandatraceofferricchloridein1LofDIwater.(cultureof algae)

See page 84 for a complete list ing of indicators and pH ranges.

Bromcresol Green

0.1% alcoholic: Dissolve 0.1 g of bromcresolgreenin75mLofethylalcohol,thendiluteto100mL.(pHindicator)

Bromcresol Green

0.04% aqueous: Dissolve 0.04 g of bromcresolgreenin50mLofDIwater,thendiluteto100mL.(pHindicator)

Bromcresol Purple

0.04% aqueous: Dissolve 0.04 g ofbromcresolpurplein50mLofDIwater,thendiluteto100mL.(pHindicator)



PrepareBufferSolutionsBuffer solutions are available from Flinn as premade solutions and readytomix capsules and envelopes. Buffers are typically mixtures of a weak acid and the salt of the acid or a weak base and its salt. This combination is called a conjugate acidbase pair and it will resist changes in pH upon addition of small amounts of acid or base. Recipes for three common buffer solutions are provided.

pH 4: Dissolve5.10gofpotassiumhydrogenphthalate(KHC8H4O4)in250mLofDIwater,add0.50mLof0.10Mhydrochloricacid,thendiluteto500mL.

pH 7: Prepare 0.10 M potassium phosphate monobasic (KH2PO4) solution by dissolving3.40g in250mLDIwater.Prepare0.20Msodiumhydroxidesolutionbydissolving0.8gin100mLDIwater.Mix250mLofthe0.10Mpotassiumphosphatesolutionand73mLof0.2Msodiumhydroxidesolution,thendiluteto500mL.

pH 10: Prepare0.025Msodiumborate solution (Na2B4O7 •10H2O) by dissolving 2.38g in250mLofDIwater.Prepare0.20Msodiumhydroxide solutionbydissolving0.8gin100mLDIwater.Mix250mLofthe0.025Msodiumboratesolutionand27mLofthe0.2Msodiumhydroxidesolution,thendiluteto500mL.




Bromine WaterAdd 1 mL of bromine to 200 mL of DIwater and stir. Keep in a tightly sealed bottle. The shelf life is poor due to evaporationofbromine.(polar/nonpolarsolubilitystudies)

Bromphenol Blue0.04% aqueous: Dissolve 0.04 g of bromphenolbluein50mLofDIwater,thendiluteto100mL.(pHindicator)

Bromthymol Blue0.04% aqueous: Dissolve 0.04 g of bromthymolbluein50mLofDIwater,thendiluteto100mL.(pHindicator)

Carbol Fuchsin (Ziehl-Nielson)Dissolve1gofbasicfuchsinin10mLof100% ethyl alcohol (absolute); set aside.Dissolve5gofphenol in100mLofDIwater. Add the two solutions together and stir. (bacterial stain,bacterial spores,andvarious cytoplasmic inclusions)

Carnoy’s FluidMixtogether10mLglacialaceticacid,30mL of chloroform, and 60 mL of 100%ethyl alcohol. (fixative for tissueused inchromosome studies)

Chlorophenol Red0.04% aqueous:Add 23.5 mL of 0.01M sodium hydroxide to 226.5 mL of DIwater.Dissolve0.1gofchlorophenolredinthissolution.(pHindicator)

Clayton Yellow1% aqueous: Dissolve 1 g of Claytonyellowin50mLofDIwater, thendiluteto100mL.(pHindicatorandfluorescentdye for microscopy)

Congo Red Indicator0.1% aqueous: Dissolve 0.1 g of Congored in50mLofDIwater, thendilute to100mL.(pHindicator)

Congo Red Stain1% aqueous: Dissolve 1 g of Congo redin100mLofDItowhichafewdropsofammonium hydroxide solution have been added.(planttissuestain)

m-Cresol PurpleAdd26.2mLof0.01Msodiumhydroxideto200mLofDIwater.Dissolve0.1gofmcresol purple in this solution, dilute to 250mL.CanomitNaOHifusingNasalt.(pHindicator)

Cresol RedAdd26.2mLof0.01Msodiumhydroxideto200mLofDIwater.Dissolve0.1gofcresol red in this solution, dilute to 250mL.CanomitNaOHifusingNasalt.(pHindicator)

Crystal Violet Indicator0.02%aqueous:Dissolve0.02gofcrystalvioletin80mLofDIwater,thendiluteto100mL.(pHindicator)

Crystal Violet Stain (Gram)Dissolve 2 g of crystal violet in 20 mLof 95% ethyl alcohol. Dissolve 0.8 g ofammoniumoxalatemonohydratein80mLofDIwaterandthenmixwiththecrystalvioletsolution.Filterifnecessary.(usedinGramstainingprocedureforbacteria)

Destaining SolutionAdd70mLglacialaceticacidto400mLmethanol. Dilute to 1 L with DI water.(removes stains from polyacrylamidegels)

Dichloroindophenol Dissolve0.025gof2,6-dichloroindophenol,sodiumsaltin80mLDIwater,thendiluteto100mL.Preparefresh.(indicatorforVitaminC)

Diphenylamine ReagentMix 1 g of diphenylamine in 100 mLglacial acetic acid and 2.75 mL of conc.sulfuric acid.Store inanamberbottle at2 °C.Warm to room temperature beforeusing.(DNA/RNAextractions)

EMB AgarSuspend36gofEMBagar in1LofDIwater and heat to boiling to dissolve the solid.Sterilize for 15min at 121 °C (15lbs. of pressure) in an autoclave or pressurecooker.Coolto50–55°Candswirltodisperse the precipitate just prior to pouring intosterilizedculturedishes. (culturemedium)

Eosin Y Indicator1%alcoholic:Dissolve1geosinYin80mL95%ethylalcohol,thendiluteto100mL.Stir and filter if necessary. (fluorescent pH indicator)

Eosin Y Stain0.5%aqueous:Dissolve0.5gofeosinYinapproximately80mLDIwater,thendiluteto100mL.Stirandfilterifnecessary.Adda few drops of chloroform as preservative. (goodcytoplasmicstain)

See page 84 for a complete list ing of indicators and pH ranges.

Eriochrome Black T Indicator1%alcoholic:Dissolve1goferiochromeblackT in 80 mL of 95% ethyl alcohol,diluteto100mLwith95%ethylalcohol.(indicatorforEDTAtitrations)

Erythrosin B Indicator1%alcoholic:Dissolve1gof erythrosinBin80mLof95%ethylalcohol,diluteto100mLwith95%ethylalcohol.(indicatorforEDTAtitrations)

Erythrosin B Stain1%aqueous:Dissolve0.1goferythrosinBin100mLofDIwater.Stirandfilterifnecessary. Add chloroform as a preservative.(biologicalstain)

Fast GreenDissolve 2 g of fast green in 100 mL ofDIwatercontaining2mLofglacialaceticacid.(tissuecellstaining)



SetupaPrepRoom

See page 1172 for a model storage/prep room diagram.

Safety Essentials• Eyewash/BodyDrench

• SpillControlandClean-upMaterials

• FireExtinguisher

• Chemical-resistantGlovesandAprons

• ChemicalSplashGoggles

• TelephoneAvailableforEmergencyUse

• ChemicalFirstAidKit

• GoodVentilation

Equipment• ElectronicBalance

• MagneticStirrers

• VolumetricFlasks

• GraduatedCylinders

• WaterPurificationSystem

• Bottles

• Labels




Safety Reference

Fehlings Solution ADissolve34.6gofcopper(II)sulfatepenta-hydrate in 500 mL DI water. CombinesolutionAandB(1:1)justbeforeuse.(testfor reducing sugars and aldehydes)

Fehlings Solution BDissolve125gofpotassiumhydroxideand173gofpotassiumsodiumtartratetetrahydrate in 500 mL of DI water. CombinesolutionAandB(1:1)justbeforeuse.(testfor reducing sugars and aldehydes)

Ferroin SolutionDissolve0.23gof iron(II) sulfatehepta-hydratein100mLofDIwater.Add0.46-gof 1,10-phenanthrolinemonohydrate andstiruntildissolved.(redoxindicator)

Fluorescein0.1% alcoholic: Dissolve 0.1 g of fluorescein in 80 mL of 95% ethyl alcohol,then dilute to 100 mL. (fluorescent pHindicator)

Formalin-Aceto-Alcohol (FAA)Mix together 50 mL of 95% ethyl alcohol, 2 mL of glacial acetic acid, 10 mLof 40% formaldehyde and 40 mL of DIwater. (preservative for algae, also a fixative)

Fuchsin, Acid, Indicator1%aqueous:Dissolve1gofacidfuchsinin80mLofDIwater,thendiluteupto100mL.(pHindicator)

Fuchsin, Acid, Stain1% aqueous: Dissolve 1 g of acid


PreparinganIodineSolution?

Iodine crystals are not directly soluble in water, which is why most waterbased iodine solutions call for potassium iodide as an ingredient. Iodine is soluble in potassium iodide solutions.

As a gen eral rule, start with approximately onefourth of the final volume of water and add the required amount of potassium iodide. Once the potassium iodide has dis solved, add the iodinecrystals.Stiruntilcompletelydissolved and bring the solution up to its final volume.

Generally, the more concentratedthe potassium iodide solution, the more readily the iodine crystals will dissolve. Iodine solutions should be prepared in a fume hood.

fuchsin in 100 mL of DI water and 1mLofglacialaceticacid.Filter ifnecessary. (staining marine algae and small crustaceans)

Fuchsin, Basic1%aqueous:Dissolve1gofbasicfuchsinin80mLofDIwater, thendilute to100mL.Filterifnecessary.(pHindicatorandbiological stain)

Fuchsin, New1%aqueous:Dissolve1gofnewfuchsinin80mLofDIwater,thendiluteto100mL.Filterifnecessary.(biologicalstain)

Gastric JuiceDissolve 5 g pepsin, 8.75 g conc.hydrochloric acid, and 2.5 g of lacticacid in 500 mL of DI water. Dilute to 1 L and stir gently to avoid foaming.(digestivestudies)

Gibberellic AcidDissolve100mgofgibberellicacidin5.0mLofethylalcohol.Diluteto1LwithDIwater.(plantgrowthhormone)

Guar GumDissolve0.5to1.0gofguargumin100mLDIwater.Makefresh.(preparationof“slime”)

Hayem’s SolutionDissolve 0.25 g of mercury (II) chloride,2.5gofsodiumsulfate,and0.5gofsodium chloride in 100 mL of DI water.(dilutingsolutionforredcellcounts)

Hematoxylin, Delafield’sDissolve 4 g of hematoxylin in 25 mLof 100% ethyl alcohol.Add 400 mL ofsaturated aqueous aluminum ammonium sulfatesolution.Exposetolightforafewdays in a cotton stoppered bottle, then filter. Add 100 mL of methyl alcohol and 100mLofglycerin.Thestainmustberipenedat room temperature for2monthsbeforeuse.Storeinawellstopperedflask.(goodgeneral stain for nonwoody plant tissue and animal tissue)

Hexamethylenediamine/Sodium HydroxideDissolve 60 g of 1,6-hexamethylenediaminein500mLofDIwater;add20gofsodium hydroxide; stir to dissolve; dilute to1L.(nylondemonstration)

Indigo CarmineDissolve 0.25 g of indigo carmine in 80mL of 50% ethyl alcohol solution. Stir,diluteto100mLwith50%ethylalcoholsolution.Preparefresh;shelf life ispoor.(pHindicator)

Iodine, Tincture ofDissolve 50 g of potassium iodide in 50mLofDIwater; add70g iodine; stir todissolvethendiluteto1Lwith95%ethylalcohol.Storeinadarkbottle.

Iodine–Potassium IodideDissolve15gofpotassiumiodidein125mLofDIwater;add3gofiodine;stirtodissolve,thendiluteto1L.Storeinadarkbottle.(starchtest)

Always store iodine solutions in PVC-coated amber, glass bottles.

Iodine Solution (0.05 M)Dissolve20gofpotassiumiodidein400mLofDIwater; add13gof iodine; stirtodissolve, thendilute to1L.Store inadark bottle.

Iodine Solution, Gram’sDissolve6.7gofpotassiumiodidein100mLofDIwater;add3.3gofiodine;stirtodissolve,thendiluteto1L.Storeinadarkbottle. (used in Gram staining procedurefor bacteria)

Iodine Solution, Lugol’sDissolve20gofpotassiumiodidein200mLofDIwater; add10gof iodine; stirtodissolve thendilute to1L.Store in adark bottle. (general biological stain andvital stain stock solution, dilute 5:1 before use.)

Knop’s SolutionAdd 1 g of potassium nitrate, 1 g of magnesium sulfate heptahydrate, 1 g of potassium phosphate dibasic, and 3 g of calcium nitrate tetrahydrate to 500 mLdistilledwater;stirthendiluteto1Lwithdistilledwater.Shakesolutionbeforeusetoredissolvethecalciumnitrate.Add10gofagarand10gofglucoseto500mLofthis solution for culturing algae. Only use distilled water when making this solution. (culturingalgae)

LimewaterAdd 25 g of calcium hydroxide to 1literofDIwater;shake;allowthesolidto settle before use. Keep container tightly closed.(detectingcarbondioxidegas)

Litmus 0.5%aqueous:dissolve0.5goflitmusin80mLofboilingDIwater.Allowsolutiontocooltoroomtemperature,diluteto100mL.Stir,filterifnecessary.(pHindicator)





Malachite Green1% aqueous: Dissolve 1 g of malachitegreenoxalate in50mLofDIwater; stirgently to prevent foaming; dilute to 100mL.Filterifnecessary.(pHindicator,stainfor plant cytoplasm)

Methyl Cellulose3%aqueous:Heat100mLofDIwaterto85°C(notboiling),shake3.0gofmethylcellulose powder into hot water, and stir rapidly while cooling the solution to 5°Cinanicewaterbath.Solutionisstableat room temper a ture but store in tightly closedcontainers.(slowingdownprotozoafor microscopy)

Methylene Blue1% aqueous: Dissolve 1 g of methylenebluein75mLofDIwater,thendiluteto100mL.(pHindicatorandstain)

Methylene Blue, Loeffler’sDissolve0.3gofmethylenebluein30mLof95%ethylalcohol;add0.01gofpotassiumhydroxideand100mLofDIwater;stir,andfilter.(bacterialstain)

Methyl Green1%alcoholic:Dissolve1gofmethylgreenin75mLof95%ethylalcohol,thendiluteto 100 mL with 95% ethyl alcohol. Stir,filterifnecessary.Use70%ethylalcoholifstainisforplanttissue.(stainforplanttissue and supravital stain for small organisms)

Methyl Orange0.1% aqueous: Dissolve 0.1 g of methylorangein75mLofDIwater,thendiluteto100mL.(pHindicator)

Methyl Red0.1%alcoholic:Dissolve0.1gofmethylred in 75 mL 95% ethyl alcohol, thendiluteto100mL.(pHindicator)

Methyl Red0.04%aqueous:Dissolve0.1gofmethylredin11.8mLof0.02Msodiumhydroxide solution; dilute to 250 mL with DIwater. IfusingNa salt, omitNaOH. (pHindicator)

Methyl Violet 2B, Indicator0.04%aqueous:Dissolve0.1gofmethylviolet 2B in 200 mL of DI water, thendiluteto250mL.(pHindicator)

Methyl Violet 2B, StainDissolve0.05gofmethylviolet2Bin100mLof0.7%sodiumchloridesolutionand1mLof1Maceticacid;stir,andfilterifnecessary.Use0.9%sodiumchloridesolutionifstaininghumanbloodcells.(stainingamphibian and human blood cells)


Methyl Violet 6B, Indicator1%aqueous:Dissolve1gofmethylviolet6B in 75 mL of DI water, then diluteto 100 mL. Stir and filter if necessary.(biologicalstain)

Millon ReagentDissolve 1 part by weight mercury in2 parts concentrated nitric acid; whenmercury has dissolved, add to 2 partswater; stir. Note: always add acid to water. (testforproteins)

Molisch ReagentDissolve5g1-naphtholin100mLof95%ethylalcohol. (test foraldehydes,sugars,and carbohydrates)

Neutral RedDissolve0.1gofneutralredin60mLof95%ethylalcohol,thendiluteto100mLwithDIwater.Stirandfilterifnecessary.(pH indicator and vital stain stock solution)

NigrosinSaturated:Dissolve3gofnigrosin(watersoluble) in100mLofDIwater.Stirandfilter if necessary. (biological stain forprotozoa)

NinhydrinAdd2.5gofninhydrinto50mLofn-butylalcohol in a600-mLbeaker.Gentlyheatand stir the solution using a magnetic stirrer/hotplate ina fumehooduntil all thesolidisdissolved.Diluteto500mLwithnbutyl alcohol. Use extreme caution when heating nbutyl alcohol, extreme fire risk. (testforproteins)

m-Nitrophenol0.3%aqueous:dissolve0.3gofm-nitrophenolin75mLDIwater, thendiluteto100mL.(pHindicator)

p-Nitrophenol0.1% aqueous: dissolve 0.1 g of p-nitrophenolin75mLDIwater, thendiluteto100mL.(pHindicator)

4-(p-Nitrophenylazo) ResorcinolDissolve 0.01 g of 4–(p-nitrophenylazo)resorcinol in 100 mL of 1 M sodiumhydroxidesolution,stir.(indicatorsolutionfor magnesium and molybdenum)

Nutrient AgarMix together 23 g of nutrient agar with 1LofDIwater.Sterilizefor15minutesat121°C(15lbsofpressure)inanautoclave or pressure cooker. Nutrient agar should be sterilized if it is being used as culture media. Cool to 50–55 °C andpourintosterilizedculturedishes.(culturemedium)

Orange G1%aqueous:Dissolve1goforangeGin75mLofDIwater,thendiluteto100mL.Stirandfilterifnecessary.(stainingplantsections)

Orange IV0.1% aqueous: Dissolve 0.1 g of orangeIV in 75 mL of DI water, then dilute to100 mL. Stir and filter if necessary. (pHindicator and biological stain)

OrceinMixtogether1goforcein,1mLofconc.hydrochloric acid, and 100 mL of 100%ethylalcohol.Shaketodissolve,letsitovernight,andfilter.(stainforelasticfibers)

PancreatinDissolve5.0gofpancreatinin500mLofDIwater,thendiluteto1L.Add0.5Msodiumbicarbonate solution dropwise until solution isneutral.(digestivestudies)



SlowMicroorganisms

Solutions of methyl cellulose arecom mon ly used in micros copy to slow themovementsofmicroorganisms—making them more readily observable. Generallyofferedasa2–3%solutionin water, its high vis cosity physically inhibits the organism. In use, the resulting dilution will depend on the amount of water present on the slide when the slowing agent is added.Someexperimentationmayberequired to find the optimal dilution for a particular organism. One technique involves dropping the methyl cellulose onto a clean slide in the form of a ring. A drop of the culture being studied is then placed into the center of the ring and a cover glass applied. As an alternative, see the listing for polyvinyl alcohol solution.




Safety Reference

PhenantholineSeeFerroinSolution,page1160.

Phenolphthalein1% alcoholic: Dissolve 1 g of phenolphthaleinin50mLof95%ethylalcohol,thendiluteto100mLwith95%ethylalcohol.Fora0.5%solution,onlyuse0.5gofphenolphthalein.(pHindicator)

Phenol Red0.02%alcoholic:Dissolve0.1gofphenolredin400mLof95%ethylalcohol,thendiluteto500mLwith95%ethylalcohol.(pHindicator)

Phenol Red, Sodium Salt0.02% aqueous: Dissolve 0.1 g ofphenol red, sodium salt in 400 mL of DI water, then dilute to 500 mL. (pHindicator)

PhloroglucinolMix0.5gphloroglucinoland50mLofDIwater.Add 50 mL of conc. hydrochloricacidandstir.Usewithin5–7days.Alwaysadd acid to water. (test for pentose orgalactose)

Polyvinyl Alcohol4%aqueous:Add40gofpolyvinylalcoholto1Lofhottapwater.Microwaveonhighforabout2minutes;stir,andheatforadditional 1–2 minute increments untildissolved. Allow solution to cool before use.(preparationof“slime”)

Potato Dextrose AgarSuspend39gofpotatodextroseagarin1LofDIwater.Heattoaboilwhilestirringconstantly.Boilfor1minute.Sterilizefor15minutesat121°C(15lbsofpressure)inanautoclaveorpressurecooker.Coolto50–55°Candpourintosterilizedculturedishes. If using for plate counts of yeasts and molds, adjust the pH to 3.5 with sterile10%tartaricacid.(culturemediumforplate counts of yeasts and molds)


PyrogallolDissolve80gofpotassiumhydroxide in65mLofDIwater,add5gofpyrogallol,stir,thendiluteto100mL.Poorshelflife,makefresh.(determiningoxygencontent)

Resazurin1%aqueous:Dissolve1gofresazurinin50 mL DI water, then dilute to 100 mL.Stirandfilterifnecessary.(biologicalstainand pH indicator)

Richard’s SolutionDissolve 6.6 g of potassium nitrate, 3.3g of potassium dihydrogen phosphate, 33.3 g sucrose, and 1.7 g of magnesiumsulfate in 1 L of DI water. (culture ofmolds)

Rhodamine B1% aqueous: Dissolve 1 g of rhodamineB in50mLDIwater, thendilute to100mL.Stir and filter if necessary. (biological stain)

Ringer’s Solution for FrogsDissolve0.14gofpotassiumchloride,6.5gofsodiumchloride,0.12gcalciumchloride,and0.2gsodiumbicarbonatein1LofDIwater.(mountingfluidandexamination of blood cells)

Ringer’s Solution for MammalsDissolve0.42gofpotassiumchloride,9.0gofsodiumchloride,0.24gcalciumchloride,and0.2gsodiumbicarbonatein1LofDIwater.(mountingfluidandexamination of blood cells)

Rose Bengal1%aqueous:Dissolve1gofrosebengalin50mLDIwater,thendiluteto100mLwithdistilledwater.Stirandfilterifnecessary.(biologicalstain)

Sabouraud Dextrose AgarSuspend65gofsabourauddextroseagarin1LofDIwater.Heattoboilingwhilestirring.Boilfor1minute.Sterilizefor15

minutesat121°C(15lbsofpressure)inan autoclave or pressure cooker. Cool to50–55°Candpourintosterilizedculturedishes.(microbiologicalculturemedium)

Safranin ODissolve 0.1 g safranin in 75 mL of DIwater,thendiluteto100mL.Filterbeforeuse.(Gramcounterstain)

Saline Solution0.75%aqueous:Dissolve7.5gofsodiumchloridein750mLofDIwater,thendiluteto1L.(Salinesolutionforbirdsandinvertebrates,use0.8%forfrogsand0.9%formammals)

Seawater (Hale’s)Dissolve 23.991 g sodium chloride,0.742 g potassium chloride, 2.240 gcalcium chloride dihydrate, 10.893g magnesium chloride hexahydrate, 9.10gsodiumsulfatedecahydrate,0.197g sodium bicarbonate, 0.085 g sodiumbromide,0.018gstrontiumchloridehexahydrate,and0.027gboricacidin800mLDIwater.Diluteupto1L.Finalsolutionhas a salinity of 34.33 0/00 (ppt) and achlorinityof190/00.Notforaquaria,onlyfor technical purposes.

Seawater Dissolve29.42gofsodiumchloride,0.5gofpotassiumchloride,3.22gmagnesiumchloride, 0.56 g sodium bromide, 1.36 gcalciumsulfate,2.4gmagnesiumsulfate,0.11 g calcium carbonate, 0.003 g ferricoxide in 1 L DI water. Not for aquaria,only for technical purposes.

Schiff’s ReagentDissolve 0.5 g of fuchsin in 500 mL ofDIwater.Decolorizesolutionbypassingsulfur dioxide gas through the solution, or add9gofsodiumbisulfiteand20mLof2Mhydrochloricacidtothefuchsinsolution.(testforaldehydes)


LaboratorySolutionsfortheScienceClassroomThe Teacher’s Handbook to Solution Preparation

Need a more complete guide on solution preparation? Laboratory Solutions for the Science Class room has been the science teacher’s #1 handbook for years. Includesexplanations of basic con cepts and vocabulary terms, detailed recipes of over 300commonly used solutions, and practical solutionmaking techniques.

Recipescoverbiology(culturemediaandbiologicalstains),chemistry and physical science solutions used in high schools. If you happen to come across a solution for which a recipe is not included, then the explanation section of the book will guide you through the steps of determining the correct procedure for making the solution.

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Schweitzer’s ReagentBoilasolutionof5gofcopper(II)sulfatepentahydrate in100mLofDIwater andslowlyadd2Msodiumhydroxidesolutionuntil precipitation is complete. Filter the copper oxide precipitate, wash with water then dissolve in the minimum volume of 4 M ammonium hydroxide.Also calledammoniacalcopperoxidesolution.(reagentfor dissolving cellulose)

Sebacoyl Chloride/Hexane SolutionMix4mLofsebacoylchloridewith96mLofhexanes.(nylondemonstration)

Starch Solution1%aqueous:Makeasmoothpastewith10gofsolublestarchandDIwater.Pourthestarchpasteinto1Lofboilingwaterwhilestirring.Cooltoroomtemperaturebeforeuse.Poorshelf life,alwaysprepare freshsolution. An easier way to make a starch solution is to generously spray ordinary spray starch (the type used for ironing)into DI water.Make fresh. (indicator foriodine)

Sudan IIIWarm73.5mLof95%ethylalcoholinawarmwaterbath.Add0.5gofsudanIIIandstir.Add75°CDIwatertojustbelowthe100mLmark.Stir andcool to roomtemperaturethendiluteto100mLwithDIwater.Filterifnecessary.(biologicalstainfor fats and lipids)

Sudan IVWarm 75 mL of 95% ethyl alcohol in awarmwaterbath.Add0.5gsudanIVandstir.Cooltoroomtemperaturethendiluteto100mLwithDIwater.Filterifnecessary.(biologicalstainforfatsandlipids)

10X TBE Electrophoresis BufferD i s s o l ve 1 0 8 g o f Tr i s b a s e[tris(hydroxymethyl)aminomethane],55gofboricacid,and7.5gofEDTA,disodiumsaltin800mLofDIwater,thendiluteto1L.Thereisnoneedtosterilizethesolution.If white clumps begin to precipitate in the solution, place the bottle in hot water until theclumpsdissolve.Storedatroomtemperature.Touseasabuffer,dilute100-mLof10Xstockto1LwithDIwater.

10X TAE Electrophoresis BufferDisso lve 48 .4 g o f Tr i s ba se[tris(hydroxymethyl)aminomethane], 11.4mLofglacialaceticacid(17.4M),and3.7gofEDTA,disodiumsaltin800mLofDIwater,thendiluteto1L.Thereisnoneedtosterilizethesolution.Storedatroomtemperature.Touseasabuffer,dilute100-mLof10Xstockto1LwithDIwater.

Thymol Blue0.04% aqueous: Mix together 0.04 g ofthymolblueand50mLofDIwater.Add5mLof0.01Msodiumhydroxidesolution;stiruntilallthesolidhasdissolved.Diluteto100mLwithDIwater.(pHindicator)

Thymol Blue0.04% aqueous: Dissolve 0.04 g ofthymol blue, sodium salt in 75 mL ofDI water, then dilute to 100 mL. (pH indicator)

Thymolphthalein0.04%alcoholic:Dissolve0.04gof thymolphthaleinin75mLofanhydrousethylalcohol,thendiluteto100mLwithanhydrousethylalcohol.(pHindicator)

Tollen’s ReagentAdd2–3dropsof2Msodiumhydroxidesolution to 5 mL of 0.2 M silver nitratesolution; add 2 M ammonium hydroxide solution dropwise until precipitate dissolves. Prepare and use this solutionimmediately; explosive fulminating silver will form if solution is allowed to stand for anyperiodoftime.(testforaldehydesandreducing sugars)

Toluidine Blue OMix1gof toluidineblueOand0.5mLof conc. hydrochloric acid into a homogeneouspaste.Whilestirring,graduallyaddthepasteto50mLofDIwater,thendiluteto 100 mL of DI water. (biological stainfor bacteria)

Universal IndicatorAdd 0.18 grams of methyl red and 0.36grams of phenolphthalein to 550 mLof 95% ethyl alcohol (C2H5OH); stir to dissolve.Inaseparatecontainer,add0.43grams of bromthymol blue to 200 mLof distilled water; stir to dissolve. Mix together the two solutions; dilute to 1 liter with distilled water. Add 1 M sodium hydroxide solution dropwise until the solution’s color is dark green; stir. (Use: pHindicator,pH4=red,pH5=orange,pH6 = yellow, pH 7 = light green, pH 8 =greenblue, pH 9 = dark bluegreen, pH 10=purple)

Winkler’s Solution #1Dissolve480gofmanganese (II)sulfatetetrahydrate in500mLofDIwater, thendilute to 1 L. (determining dissolvedoxygen)

Winkler’s Solution #2Dissolve500gofsodiumhydroxideand135gofsodiumiodidein700mLofDIwater,thendiluteto1L.Alargeamountof heat is generated, place the mixing container inanicewaterbath.Store inaplastic container. (determining dissolvedoxygen)

Wright’s StainDissolve 2.5 g of Wright’s stain in 75 mL of absolute methyl alcohol, thendilute to 100 mL with absolute methylalcohol.Stirandfilterifnecessary.(biological stain for blood)

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preparation • over 300 recipes of commonmolarity the most common unit of solution concentration is...

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