25g of a sample of ferrous sulphate was dissolved in water containing dilute h2s04 and the volume made up to one litre. 25ml of this solution required 20ml of N/10 kmn04 solution for complete oxidation. Calculate the percentage of f2s04 7h20 in the sample

1 g of mixture of na2c03 and k2c03 was mole made upto 250ml is aqueous solution 25ml of this solution was neutralized 20ml of hcl of unknown required 16.24ml of 0.1N agn03 for precipitation. Calculate the % k2c03 is mixture , conc of hcl in g/litre and molarity of hcl.