(English Medium) ICSE Class 9 - CISCE Question Bank Solutions

Give balanced equation to show how temporary hardness in water can be removed by boiling.

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?

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

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?

Using given sample of temporary and permanent hard water, soft water, ordinary soap, detergent and washing soda how would you remove temporary hardness and permanent hardness from water using a chemical compound?

Using given sample of temporary and permanent hard water, soft water, ordinary soap, detergent and washing soda how would you prove the advantage of detergent over soap.

Fill in the blank:

Hard and soft water can be distinguished using _____.

Explain the meaning of the terms – hard water & soft water.

State the causes of hardness in water.

Give two natural sources of hard water.

Both temporary & permanent hardness in water can be removed by addition of washing soda. Give balanced equations for the same.

A sample of water is given in a trough. State how would you prove experimentally whether the given sample is hard water or soft water.

Two samples of water are placed in a beaker individually. State how you will determine experimentally which of the two samples contains permanent hard water.

State what are synthetic detergents. Explain experimentally how you will determine the advantage of synthetic detergents over soap using a sample of hard water.

Select the correct answer from the choice given in the options.

A substance which causes hardness in water _____.

Name or state the following:

A substance added to remove both temporary and permanent hardness in water.

Explain the reason for the chemical activity of an atom with reference to its electronic configuration.

If an element is in Group 17 [or Group 7A] is it likely to be metallic or non- metallic in character?

Define the following term: 

Efflorescence

Define the following term: 

Hygroscopy