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

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

Write the balanced equation and give your observation when the following metal reacts:

Sodium with cold water

Write the balanced equation and give your observation when the following metal reacts:

Calcium with cold water

Write the balanced equation and give your observation when the following metal reacts:

Magnesium with boiling water

Write the balanced equation and give your observation when the following metal reacts:

Magnesium with steam

Give the balanced equation of the reaction.

Choose the correct option:

The composition of the nucleus of deuterium is

Choose terms from the options given in brackets to complete this sentence.

A metal …………….. hydrogen in the activity series gives hydrogen with …………… acid or …………… acid.

(above, below, dilute hydrochloric, concentrated hydrochloric, dilute sulphuric). 

Correct the following statement:

Hydrogen is dried by passing it through conc. H₂SO₄.

Give a test to differentiate between two gas jars – one containing pure hydrogen and the other hydrogen-air mixture.