Percentage Purity

1.17 g an impure sample of oxalic acid dihydrate was dissolved and make up of 200 ml with water. 10 ml of this solution in acidic medium required 8.5 ml of a solution of potassium permanganate containing 3.16 g per litre of solution. The percentage purity of oxalic acid will be:

Specific rotation of sugar solution is 0.5 deg m^(2)//kg . 200kgm^(-3) of impure sugar solution is taken in a sample polarimeter tube of length 20 cm and optical rotation is found to be 19^(@) . The percentage of purity of sugar is :

Specific rotation of sugar solution is 0.01 SI units. 200 kg-m^(-3) of impure sugar solution is taken in a polarimeter tube of length 0.25m and an optical rotation of 0.4 rad is observed. The percentage of purity of sugar in the sample is

The impure 6g of NaCl is dissolved in water and then treated with excess of silver nitrate solution. The mass of p[recipitate of silver chloride is found to be 14g. The % purity of NaCl solution would be: