Question

5. Calculate the amount of F.A.S. required to prepare M/20 standard solution of F.A.S.​

Answer 1

Answer:

Here the volume of M/20 FAS required is not given.

If we assume 1000 ml of M/20 FAS is to be prepared. Molecular Mass of FAS = 392

Its M.F is FeSO4.(NH4)2SO4.6 H2O, whose Molecular Mass is 392.

So if we dissolve (392/20=) 19.6 g of FAS in a 1000 ml. standard flask, with a small addition of dil. H2SO4, to avoid turbitidity and then distilled water is added up to the mark and shaken well for uniform concentration, we get M/20 or 0.05M Solution.

1 mole of FAS (392-g) in 1000 ml gives = 1M Solution.

0.1 mole of FAS (392/10= 39.2 )-g in 1000 ml gives 0.1M Solution.

0.05 mole of FAS (392/20= 19.6) g in 1000 ml gives M/20 or 0.05M Solution.

OK

Explanation: