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


This 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
Na2CO3, 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)2SO4. 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
HO2C(CH2)4CO2H 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
C6H5COOH, 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
CaCO3, 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
H2C2O4.2H2O, 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(C8H4O4), 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(IO3)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
Na2CO3, 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
Na2C2O4, 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
NaB4O7.10H2O, 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
HO2CCH2CH2CO2H, 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
H2NSO3H, 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
H2SO4, 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
H2N.C(CH2OH)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


5Na2C2O4 + 2KMnO4 + 8H2SO4 = 10CO2 + 2MnSO4 + 5Na2SO4 + 8H2O
Reaction of Potassium permanganate and Sodium oxalate
width=""> Ammonium oxalate
(NH4)2C2O4, 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
FeSO4(NH4)2SO4.6H2O, 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
H2O2, 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)
FeNH4(SO4)2.12H2O, 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.)
H2C2O4, 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
KMnO4, 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
NaNO2, 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
Na2C204, 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


K2Cr2O7 + 6Fe(NH4)2(SO4)2 + 7H2O4 = 3Fe2(SO4)3 + Cr2(SO4)3 + K2SO4 + 6(NH4)2SO4 + 7H2O
Reaction of Potassium dichromate and Ammonium ferrous sulphate
Potassium dichromate
K2Cr2O7, 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
KIO3, 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
FeCO3, 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


I2 + 2Na2S2O3 = Na2S4O6 + 2NaI
Reaction of Iodine and Sodium thiosulphate
Sodium thiosulphate
Na2S2O3.5H2O, 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
KIO3, 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, I2
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
CuSO4.5H2O, 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
CuSO4, 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
CaOCl2, 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
Na2SO3.5H2O, 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). AgNO3 + NaCl = AgCl = NaNO3 and K2CrO4 + 2AgNO3 = Ag2CrO4 + 2KNO3
(2). AgNO3 + KSCN = AgSCN + KNO3 and AgSCN + Fe3+ indicator = [FeSCN]+2
Silver nitrate
AgNO3, 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
K2CrO4, 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
NH4CNS, 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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