ICSE ICSE Class 8 - CISCE Question Bank Solutions for Chemistry

Give balanced equation for the following conversion:

Zinc to sodium zincate – using an alkali.

Give balanced equation for the following conversion:

Zinc to sodium zincate – using an alkali.

Give balanced equation for the following conversion:

Acidified water to hydrogen – by electrolysis.

Give balanced equation for the following conversion:

Acidified water to hydrogen – by electrolysis.

Give reason for the following:

Copper does not displace hydrogen from dilute hydrochloric acid, but zinc does.

Give reason for the following:

Copper does not displace hydrogen from dilute hydrochloric acid, but zinc does.

Give reason for the following:

In the laboratory preparation of hydrogen from zinc and dilute hydrochloric acid – the zinc used granulated zinc.

Give reason for the following:

In the laboratory preparation of hydrogen from zinc and dilute hydrochloric acid – the zinc used granulated zinc.

Define the term ‘valency’.

State a reason why the symbol of calcium is ‘Ca’ and of copper is ‘Cu’

Give a reason – Magnesium [2, 8, 2] has valency 2+.

State the valency of the following metallic element and write symbol with the valency
Potassium

State the valency of the following metallic element and write symbol with the valency
Sodium

State the valency of the following metallic element and write symbol with the valency
Calcium

State the valency of the following metallic element and write symbol with the valency
Magnesium

State the valency of the following metallic element and write symbol with the valency
Zinc

State the valency of the following metallic element and write symbol with the valency
Aluminium

State the valency of the following metallic element and write symbol with the valency
Chromium

Certain metal exhibit variable valencies which include valencies: 1+, 2+, 3+, and 4+.
State the variable valency of the following metal.
Copper
write symbol with the variable valency

Certain metal exhibit variable valencies which include valencies: 1+, 2+, 3+, and 4+.
State the variable valency of the following metal.
Silver
write symbol with the variable valency