Question

Using given sample of temporary and permanent hard water, soft water, ordinary soap, detergent and washing soda how would you remove temporary hardness from water without using a chemical compound?

Answer 1

Temporary hardness can be removed by heating the hard water.

Experiment
Temporary hard water softened by heating

1. Temporary hard water is taken in a beaker and heated
2. After the gases escape out, the water is filtered through a filter paper.
3. Ordinary soap is rubbed – inside the filtered solution.

Observation

1. The boiled and filtered sample of – temporary hard water lathers readily with soap.

Result

1. Temporary hard water can be – softened by heating.

\[\ce{\underset{\text{[in temporary hard water]}}{Ca(HCO3)2} ->\underset{\text{[ppt. filtered out]}}{CaCO3↓} +\underset{\text{[filtered water is soft]}}{CO2 + H2O}}\]