Question

Solve: 0.5 gms of CaCO3 was dissolved in dil HCL and diluted to 1000ml. 50ml of this solution required 48 ml of EDTA solution for titration. 50ml of hard water sample required 15ml of EDTA solution for titration. 50ml of same water after boiling filtering etc required 10ml of EDTA solution. Calculate different kinds of hardness in ppm

Answer 1

Explanation:

Answer:

50 ml SHW required = 48 ml of EDTA solution

∴ 1 ml EDTA solution = 50/48 mgs CaCO3CaCO3 equivalent hardness.

50 ml water sample = 15 ml EDTA solution.

∴ hardness of sample = (15 * 50/48) mgs CaCO3 equivalents for 50 ml sample.

Hardness per litre of sample = (15 * 50/48)* 1000/50 mgs/lit.

Total hardness = 312.50 ppm

50 ml water sample after boiling = 10 ml EDTA solution

Permanent hardness of sample = 10 * 50/48 mgs CaCO3CaCO3 equivalent for 50 ml.

Permanent hardness of one litre sample = (10 * 50/48)*1000/50 mgs/lit.