ICSE ICSE Class 8 - CISCE Question Bank Solutions for Chemistry

State whether the following ion or radical given below of a non-metallic element exhibits valency: 1^–, 2^– or 3^–. (write the ion or radical with the correct valency).

Zincate

State whether the following ion or radical given below of a non-metallic element exhibits valency: 1^–, 2^– or 3^–. (write the ion or radical with the correct valency).

Plumbite

State whether the following ion or radical given below of a non-metallic element exhibits valency: 1^–, 2^– or 3^–. (write the ion or radical with the correct valency).

Phosphate

State whether the following ion or radical given below of a non-metallic element exhibits valency: 1^–, 2^– or 3^–. (write the ion or radical with the correct valency).

Nitride

Complete the statement given below by filling in the blanks with the correct words.

From the elements – He, Br, Pt and O; the element which forms a polyatomic molecule is ________ and which is liquid at room temperature is ________.

Differentiate between direct combination reaction and a decomposition reaction.

Classify the following reaction into – 

1. Direct combination 
2. Decomposition
3. Displacement
4. Double decomposition

The reaction is – Zinc hydroxide on heating gives zinc oxide and water.

Give a balanced equation for –

A thermal decomposition reaction involving heat on limestone [calcium carbonate]

Give a balanced equation for –

An electrolytic decomposition reaction involving a neutral liquid

Give a balanced equation for –

A double decomposition neutralization reaction involving an acid and a base

Give a balanced equation for –

A white precipitate obtained during a double decomposition reaction involving a silver salt with sodium salt.

Complete the statement by filling in the blank with the correct word:

Decomposition of silver salts in the presence of sunlight is an example of _________.

Give a balanced equation for the following type of reaction:

A thermal decomposition reaction in which a metallic nitrate decomposes to give – a basic oxide.

Give a balanced equation for the following type of reaction:

A thermal decomposition reaction in which a compound decomposes to give two new compounds.

Differentiate between the following:

Thermal decomposition and thermal dissociation.

Differentiate between the following:

Electrolytic decomposition and photochemical decomposition.

Fill in the blank.

The chemical change involving iron and hydrochloric acid illustrates a ...............reaction.

Classify the following reaction as combination, decomposition, displacement, precipitation and neutralization. Also balance the equation.

\[\ce{AgNO3_{(aq)} + NaCl_{(aq)}-> AgCl_{(s)} + NaNO3}\]

Name a process by which hydrogen gas is manufactured.

Explain the following type of chemical reaction, giving two examples for it:

Displacement reaction