## How to make up 250ml 0.05M and 0.1N Volumetric analysis

Primary StandardsThis page gives the weight of pure, dry salt required to make up a 250 ml volumetric analysis primary standard for titrations against acid base, permanganate, dichromate, iodine, sodium thiosulphate and silver nitrate.

Concentrations are expressed in normality or molarity and given in values of 0.1N, 0.05M, or 0.002M.

Example for the info on this page:

Sodium carbonate

Na_{2}CO_{3}, FW = 106, 1M = 106g/l

Eq.wt. = 53g/l = 1N = 0.5M

1 liter = 5.30g/l = 0.1N = 0.05M

250ml = 1.325g = 0.IN or 0.05M std. soln.

Dissolve 1.325g of the salt in 250ml volumetric flask to give a 0.05M or a 0.1N equivalent std soln.

In this example, the FW or Formula weight (Molecular weight) of the salt is 106. Eq.wt. is the Equivalent Weight which is 53 grams per liter. And 1.325 grams (5.30 g/l divided by 4) dissolved in 250 ml volumetric flask will give a 0.1N standard solution or a 0.05M standard solution.

## Acid / Base Titrations

Ammonium sulphate

NH4)_{2}SO4. FW = 132.14, 1M = 132.14g/l

Eq.wt. = 66.07g/l = 1N = 0.5M

1 liter = 6.607g/l = 0.1N =0.05M

250ml = 1.652g = 0.IN or 0.05M std. soln.

Dissolve 1.652g of the salt in 250ml volumetric flask to give a 0.05M or a 0.1N equivalent std soln.

Adipic acid

HO_{2}C(CH2)_{4}CO_{2}H FW = 146.4, 1M = 146.4g/l

Eq.wt. = 73.03g/l =1N = 0.5M

1 liter = 7.303g/l = 0.1N = 0.05M

250ml = 1.83g = 0.1N or 0.05M std. soln.

Dissolve 1.83g of the salt in 250ml volumetric flask to give a 0.05M or a 0.1N equivalent std soln.

Barium hydroxide

Ba(OH)_{2}.8H2O, FW = 315.48, 1M = 315.48g/l

Eq.wt. = 157.5g/l = 1N or 0.5M

1 liter = 15.75g/l = 0.1N = 0.05M

250ml = 3.94g =0.1N or 0.05M std. soln.

Dissolve 3.94g of the salt in 250ml volumetric flask to give a 0.05M or a 0.1N equivalent std soln.

Benzoic acid

C_{6}H_{5}COOH, FW = 122.12, 1M = 122.12g/l

Eq.wt. = 61.06g/l = 1N = 0.5M

1 liter = 6.106g/l = 0.1N = 0.05M

250ml = 1.52g = 0.1N or 0.05M std. soln.

Dissolve 1.52g of the salt in 250ml volumetric flask to give a 0.05M or a 0.1N equivalent std soln.

Calcium carbonate

CaCO_{3}, FW = 100.00, 1M = 100g/l

Eq.wt. = 50g/l = 1N = 0.5M

1 liter = 5.0g/l = 0.1N =0.05M

250ml = 1.25g = 0.IN or 0.05M std. soln.

Dissolve 1.25g of the salt in 250ml volumetric flask to give a 0.05M or a 0.1N equivalent std soln.

Furroic acid

FW = 112.08, 1M = 112.08g/l

Eq.wt. = 112.08 = 1N = 1M

1 liter = 11.2g/l = 0.1N =0.1M

250ml = 2.8g = 0.IN or 0.1M std. soln.

Dissolve 2'8g of the salt in 250ml volumetric flask to give a 0.1M or a 0.1N equivalent std soln.

Hydrochloric acid

HCl, FW = 36.5, Density = 1.2

1M = 83mls = 1N = 1M (Use 86mls)

250ml = 2mls = 0.1N = 0.1N

1 liter = 8.6mls = 0.1N or 0.1M soln.

Measure 2mls of the acid in 250ml volumetric flask to give a 0.1M or a 0.1N equivalent soln.

Oxalic acid

H_{2}C_{2}O_{4}.2H_{2}O, FW = 126.07, 1M = 126.07g/l

Eq.wt. = 63.03g/l = 1N = 0.5M

1 liter = 6.303g/l = 0.1N =0.05M

250ml = 1.575g = 0.IN or 0.05M std. soln.

Dissolve 1.575g of the salt in 250ml volumetric flask to give a 0.05M or a 0.1N equivalent std soln.

Potassium hydrogen phthalate

KH(C_{8}H_{4}O_{4}), FW = 204.23, 1M 204.23g/l

Eq.wt. = 204.23g/l = 1N = 1M

1 liter = 204.23g/l = 0.1N =0.1M

250ml = 5.105g = 0.IN or 0.1M std. soln.

Dissolve 5.105g of the salt in 250ml volumetric flask to give a 0.1M or a 0.1N equivalent std soln.

Potassiun hydrogen iodate

KH(IO_{3})_{2}, FW = 389.92, 1M = 389.82g/l

Eq.wt. = 77.98g/l = 1N = 0.2M

1 liter = 7.798g/l = 0.1N =0.02M

250ml = 1.95g = 0.IN or 0.02M std. soln.

Dissolve 1.95g of the salt in 250ml volumetric flask to give a 0.02M or a 0.1N equivalent std soln.

Sodium carbonate

Na_{2}CO_{3}, FW = 106, 1M = 106g/l

Eq.wt. = 53g/l = 1N = 0.5M

1 liter = 5.30g/l = 0.1N =0.05M

250ml = 1.325g = 0.IN or 0.05M std. soln.

Dissolve 1.325g of the salt in 250ml volumetric flask to give a 0.05M or a 0.1N equivalent std soln.

Sodium hydroxide

NaOH, FW = 40, 1M = 40g/l

Eq.wt. = 40.00g/l = 1N = 1M

1 liter = 4.0g/l = 0.1N =0.1M

250ml = 1.00g = 0.IN or 0.1M std. soln.

Dissolve 1.00g of the salt in 250ml volumetric flask to give a 0.1M or a 0.1N equivalent soln.

Sodium oxalate

Na_{2}C_{2}O_{4}, FW = 134.00, 1M = 134g/l

Eq.wt. = 134g/l = 1N = 1M

1 liter = 13.40g/l = 0.1N = 0.1M

250ml = 3.35g = 0.IN or 0.1M std. soln.

Dissolve 3.35g of the salt in 250ml volumetric flask to give a 0.1M or a 0.1N equivalent std soln.

Sodium tetraborate

NaB_{4}O_{7}.10H_{2}O, FW = 381.37, 1M = 381.37g/l

Eq.wt. = 190.685g/l = 1N = 0.5M

1 liter = 190.68g/l = 0.1N = 0.05M

250ml = 4.767g = 0.IN or 0.05M std. soln.

Dissolve 4.767g of the salt in 250ml volumetric flask to give a 0.05M or a 0.1N equivalent std soln.

Succinic acid

HO_{2}CCH_{2}CH_{2}CO_{2}H, FW = 118.09, 1M = 118.09g/l

Eq.wt. = 59.045g/l = 1N = 0.5M

1 liter = 5.9.045g/l = 0.1N = 0.05M

250ml = 1.475g = 0.IN or 0.05M std. soln.

Dissolve 1.475g of the salt in 250ml volumetric flask to give a 0.05M or a 0.1N equivalent std soln.

Sulphamic acid

H_{2}NSO_{3}H, FW = 97.09, 1M = 97.09g/l

Eq.wt. = 97.09g/l = 1N = 1M

1 liter = 9.709g/l = 0.1N =0.1M

250ml = 2.427g = 0.IN or 0.1M std. soln.

Dissolve 2.427g of the salt in 250ml volumetric flask to give a 0.1M or a 0.1N equivalent std soln.

Sulphuric acid

H_{2}SO_{4}, FW = 98.08, Density = 1.8

1 liter = 56mls = 2N = 1M

1 liter = 28mls = 1N = 0.05M

1 liter = 2.8mls = 0.1N or 0.05M (use 3 mls)

250ml = 0.7mls = 0.1N = 0.05M std.

Measure 0.7mls of the acid in 250ml volumetric flask to give a 0.05M or a 0.1N equivalent soln.

Tris (hydroxymethyl)-aminomethane

H_{2}N.C(CH_{2}OH)_{3}, FW = 121.14, 1M = 121.14g/l

Eq.wt. = 121.14g/l = 1N = 1M

1 liter = 12.114g/l = 0.1N = 0.1M

250ml = 3.023g = 0.IN or 0.1M std. soln.

Dissolve 3.023g of the salt in 250ml volumetric flask to give a 0.1M or a 0.1N equivalent std soln.

## Titrations with Permanganate

5Na_{2}C_{2}O_{4}+ 2KMnO_{4}+ 8H_{2}SO_{4}= 10CO_{2}+ 2MnSO_{4}+ 5Na_{2}SO_{4}+ 8H_{2}O

Reaction of Potassium permanganate and Sodium oxalatewidth=""> Ammonium oxalate

(NH4)_{2}C_{2}O_{4}, FW = 124, 1M = 124g/l

Eq.wt. = 62g/l = 1N = 0.5M

1 liter = 6.20g/l = 0.1N = 0.05M

250ml = 1.55g = 0.IN or 0.05M std. soln.

Dissolve 1.55g of the salt in 250ml volumetric flask to give a 0.05M or a 0.1N equivalent std soln.

width=""> Ferrous ammonium sulphate

FeSO_{4}(NH_{4})_{2}SO_{4}.6H_{2}O, FW = 392, 1M = 392g/l

Eq.wt. = 392g/l = 1N = 1M

1 liter = 39.20g/l = 0.1N = 0.1M

250ml = 9.8g = 0.IN or 0.1M std. soln. (add a few drops of conc. H2SO4 to clear)

Dissolve 9.8g of the salt in 250ml volumetric flask to give a 0.1M or a 0.1N equivalent std soln.

Hhdrogen peroxide

H_{2}O_{2}, FW = 34. Eq. = 17g/l

10 Vol. = 3%

20 Vol. = 6% = 1.8M

100 Vol. = 30%

250ml 0.05M = 12.50ml of 20 Vol. = 0.1N

Dissolve 12.50 mls of 20 vol in 250ml volumetric flask to give a 0.05M or a 0.1N equivalent std soln.

1 liter 0.05M = 50ml of 20 Vol. = 0.1N (add 2 mls conc. H2SO4 per liter soln)

Volume strength = 11.2/34 x strength of peroxide in g/l

Iron allum (ferric ammonium sulphate)

FeNH_{4}(SO4)_{2}.12H_{2}O, FW = 482.19, 1M = 482.19g/l

Eq.wt. = 241g/l = 1N = 0.5M

1 liter = 24.10g/l = 0.1N = 0.05M

250ml = 6.02g = 0.IN or 0.05M std. soln.

Dissolve 6.02g of the salt in 250ml volumetric flask to give a 0.05M or a 0.1N equivalent std soln.

Oxalic acid (anhyd.)

H_{2}C_{2}O_{4}, FW = 90, 1M = 90gm/l

Eq.wt. = 45g/l = 1N = 0.5M

1 liter = 4.5g/l = 0.1N = 0.05M

250ml = 1.125g = 0.IN or 0.05M std. soln.

Dissolve 1.125g of the salt in 250ml volumetric flask to give a 0.05M or a 0.1N equivalent std soln.

Potassium permanganate

KMnO_{4}, FW =158.04, 1M = 158.04g/l

Eq. ==31.6g/l

Eq.wt. = 31.6g/l = 1N = 0.2M

1 liter = 3.16g/l = 0.1N = 0.02M (boil to dissolve crystals, then dilute to 1 liter)

250ml = 0.79g = 0.IN or 0.02M std. soln.(dissolve in hot water)

Dissolv 0.79g of the salt in 250ml volumetric flask to give a 0.02M or a 0.1N equivalent std soln.

Sodium nitrite

NaNO_{2}, FW = 69.00, 1M = 69g/l

Eq. = 34.56/l

Eq.wt. = 34.56g/l = 1N = 0.5M

1 liter = 3.456g/l = 0.1N = 0.05M

250ml = 0.86g = 0.IN or 0.05M std. soln. (use 1 gram)

Dissolve 0.86g of the salt (use 1g) in 250ml volumetric flask to give a 0.05M or a 0.1N equivalent std soln.

Sodium oxalate

Na_{2}C_{2}0_{4}, FW = 134, 1M = 134g/l

Eq. = 67g/l

Eq.wt. = 67g/l = 1N = 0.5M

1 liter = 6.7g/l = 0.1N = 0.05M

250ml = 1.675g = 0.IN or 0.05M std. soln.

Dissolve 1.675g of the salt in 250ml volumetric flask to give a 0.05M or a 0.1N equivalent std soln.

## Titrations with Dichromate

K_{2}Cr_{2}O_{7}+ 6Fe(NH_{4})_{2}(SO_{4})_{2}+ 7H_{2}O_{4}= 3Fe_{2}(SO_{4})_{3}+ Cr_{2}(SO_{4})_{3}+ K_{2}SO_{4}+ 6(NH_{4})_{2}SO_{4}+ 7H_{2}O

Reaction of Potassium dichromate and Ammonium ferrous sulphatePotassium dichromate

K_{2}Cr_{2}O_{7}, FW = 294, 1M = 294g/l

Eq.wt. = 49g/l = 1N = 0.167M

1 liter = 4.90g/l = 0.1N = 0.0167M

250ml = 1.22g = 0.IN or 0.05M std. soln.

Dissolve 1.22g of the salt in 250ml volumetric flask to give a 0.05M or a 0.1N equivalent std soln.

Potassium iodate

KIO_{3}, FW = 214, 1M = 214g/l

Eq.wt. = 35.73g/l = 1N = 0.167M

1 liter = 3.573g/l = 0.1N = 0.0167M

250ml = 0.892g = 0.IN or 0.0167M std. soln.

Dissolve 0.892g of the salt in 250ml volumetric flask to give a 0.0167M or a 0.1N equivalent std soln.

Tin, Sn,

FW = 119.0

Tin (11) chloride(use metallic tin dissolved in conc. HCl)

Eq.wt. = 59.5g/l = 1N = 0.5M

1 liter = 5.95g/l = 0.1N = 0.05M

250ml = 1.49g = 0.IN or 0.05M std. soln.

250ml 0.05M = 1.49g = 0.1N

Dissolve 1.49g of the metal in conc HCl in 250ml volumetric flask to give a 0.05M or a 0.1N equivalent std soln.

Spathic iron ore

FeCO_{3}, FW = 116, 1M = 116g/l

Eq. = 116g/l

Eq.wt. = 116g/l = 1N = 1M

1 liter = 11.6g/l = 0.1N = 1M

250ml = 2.9g = 0.IN or 0.1M std. soln.

Dissolve 2.9g in 250ml volumetric flask to give a 0.1M or a 0.1N equivalent std soln.

## Titrations with iodine and Thiosulphate

I_{2}+ 2Na_{2}S_{2}O_{3}= Na_{2}S_{4}O_{6}+ 2NaI

Reaction of Iodine and Sodium thiosulphateSodium thiosulphate

Na_{2}S_{2}O_{3}.5H_{2}O, FW = 248.18, 1M = 248.18g/l

Eq.wt. = 248.18g/l = 1N = 1M

1 liter = 24.818g/l = 0.1N = 0.1M

250ml = 6.20g = 0.IN or 0.1M std. soln.

Dissolve 6.20g of the salt in 250ml volumetric flask to give a 0.1M or a 0.1N equivalent std soln.

Potassium iodide

KI, FW = 166, 1M = 166g/l

Eq.wt. = 166g/l = 1N = 1M

1 liter = 16.6g/l = 0.1N = 0.1M

250ml = 4.15g = 0.IN or 0.1M std. soln.

Dissolve 4.15g of the salt in 250ml volumetric flask to give a 0.1M or a 0.1N equivalent std soln.

Potassium iodate

KIO_{3}, FW = 214, 1M = 214g/l

Eq.wt. = 35.73g/l = 1N = 0.167M

1 liter = 3.573/g/l = 0.1N = 0.0167M

250ml = 0.892g = 0.IN or 0.0167M std. soln.

Dissolve 0.892g of the salt in 250ml volumetric flask to give a 0.0167M or a 0.1N equivalent std soln.

Iodine, I_{2}

FW = 253.18, 1M = 253.18g/lg/l

Eq.wt. = 126.59g/l = 1N = 0.5M

1 liter = 12.659g/l = 0.1N = 0.05M (use 13 grams)

250ml = 3.16g = 0.IN or 0.05M std. soln.

Dissolve 3.16g of the salt (add 5g solid KI) in 250ml volumetric flask to give a 0.05M or a 0.1N equivalent std soln.

1 liter 0.05M = 12.7g = 0.1N

(use 13g Iodine and add 25g KI

Copper sulphate

CuSO_{4}.5H_{2}O, FW = 249.68, 1M =249.68g/l

Eq.wt. = 249.68g/l = 1N = 1M

1 liter = 24.968g/l = 0.1N = 0.1M

250ml = 6.24g = 0.IN or 0.1M std. soln.

Dissolve 6.24g of the salt in 250ml volumetric flask to give a 0.1M or a 0.1N equivalent std soln.

Note: add anhy. NaCO3 untill a slight permanent

bluish colour is formed. Add a little acetic acid to

get a clear blue colour, then make up to the mark.Copper sulphate, anhydrous

CuSO_{4}, FW = 159.6, 1M = 159.6g/l

Eq.wt. = 159.6g/l = 1N = 1M

1 liter = 15.96g/l = 0.1N = 0.1M

250ml = 4.0g = 0.IN or 0.1M std. soln.

Dissolve 4.0g of the salt in 250ml volumetric flask to give a 0.1M or a 0.1N equivalent std soln.

Bleaching powder

CaOCl_{2}, FW = 145, 1M = 145g/l

Eq.wt. = 72.5g/l = 1N = 0.5M

1 liter = 7.25g/l = 0.1N = 0.05M

250ml = 1.81g (use 2.5g) = 0.IN or 0.05M std. soln.

Dissolve 2.5g of the salt in 250ml volumetric flask to give a 0.05M or a 0.1N equivalent soln.

Sodium sulphite

Na_{2}SO_{3}.5H_{2}O, FW = 126.04, 1M = 126.04g/l

Eq.wt. = 63g/l = 1N = 0.5M

1 liter = 6.3/l = 0.1N = 0.05M

250ml = 1.57g = 0.IN or 0.05M std. soln.

Dissolve 1.57g of the salt in 250ml volumetric flask to give a 0.05M or a 0.1N equivalent std soln.

## Titrations with Silver Nitrate

(1). AgNO_{3}+ NaCl = AgCl = NaNO_{3}and K_{2}CrO_{4}+ 2AgNO_{3}= Ag_{2}CrO_{4}+ 2KNO_{3}

(2). AgNO_{3}+ KSCN = AgSCN + KNO_{3}and AgSCN + Fe^{3+}indicator = [FeSCN]^{+2}Silver nitrate

AgNO_{3}, FW = 170, Eq. =170g/l

250ml 0.1M = 4.25g = 0.1N

Dissolve 4.25g of the salt in 250ml volumetric flask to give a 0.1M or a 0.1N equivalent std soln.

Sodium chloride

NaCl, FW = 58.5, 1M = 58.5g/l

Eq.wt. = 58.5g/l = 1N = 1M

1 liter = 5.85g/l = 0.1N = 0.1M

250ml = 1.4625g = 0.IN or 0.1M std. soln.

Dissolve 1.4625g of the salt in 250ml volumetric flask to give a 0.1M or a 0.1N equivalent std soln.

Potassium chromate

K_{2}CrO_{4}, FW = 194.20, 1M = 194.20g/l

Eq.wt. = 32.4g/l = 1N = 0.167M

1 liter = 3.24g/l = 0.1N = 0.0167M

250ml = 0.81g = 0.IN or 0.0167M std. soln.

Dissolve 0.81g of the salt in 250ml volumetric flask to give a 0.0167M or a 0.1N equivalent std soln. (add a few mls dil. H2SO4 to clear)

Ammonium thiocyanate

NH_{4}CNS, FW = 76.12, 1M = 76.12g/l

Eq.wt. = 76.12g/l = 1N = 1M

1 liter = 7.612g/l = 0.1N = 0.1M

250ml = 1.9g = 0.IN or 0.1M std. soln.

Dissolve 1.9g of the salt in 250ml volumetric flask to give a 0.1M or a 0.1N equivalent std soln.

Potassium thiocyanate

KCNS, FW = 97.18, 1M = 97.18g/l

Eq.wt. = 97.18g/l = 1N = 1M

1 liter = 9.718g/l = 0.1N = 0.1M (use 12g)

250ml = 2.429g = 0.IN or 0.1M std. soln.

Dissolve 2.429g (use 3g) of the salt in 250ml volumetric flask to give a 0.1M or a 0.1N equivalent std soln.

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