Question

Using given sample of temporary and permanent hard water, soft water, ordinary soap, detergent and washing soda how would you distinguish between hard and soft water?

Answer 1

Differentiating hard water from soft water

1. Two unknown samples ‘X’ and ‘Y’ containing hard water and soft water are taken – separately in the trough or beaker.
2. Ordinary soap is rubbed by the hands – inside each sample.

Observation

1. One sample of water ‘X’ lathers with soap.
2. The sample of water ‘Y’ does not lather with

Result

1. Sample ‘X’ which lathers is – soft water.
2. Sample ‘Y’ which does not lather is – hard