Question

8.
Give reasons for the following:
a) Sodium is stored under kerosene.
b) Iron cannot displace zinc from its solution.
c) A copper vessel acquires a dull green coating if exposed to moist air for long.
d) Silver jewellery turns dark over a period of time.​

Answer 1

a) Sodium is stored under kerosene because they are explosive

Answer 2

Answer:

1. sodium is stored in kerosene because it is a highly reactive metal and it catches fire quickly when it comes in contact with oxygen and carbon dioxide present in the air.

2. Iron cannot displace zinc from its solution because iron js more reactive than zinc

3. this is because when copper come in contact with air or any acid , it gets corroded due to the process of corrosion.

4. This is also due to corrosion when silver comes in contact with air , it gets corroded and the black colour is known as the silver sulphide