Question

Water contains 88.89% of A by weight is decomposed into its elements B and oxygen. Pure C is a poor conductor of electricity and hence it is acidified using dilute sulphuric acid. When electric current is passed through acidulated water, using platinum electrones, hydrogen gas is evolved at cathode and oxygen gas is evolved at D.

What is D?

• A. Anode
• B. Electrolyte
• C. Catalyst
• D. Cathode

Answer 1

Answer: (A)

The correct option is A Anode

Percentage of oxygen in water

$=\frac{weightofoxygeninwater}{weightofwater}\times 100$

$=\frac{16}{18}\times 100$

$=$ 88.89%

Thus, water contains 88.89% of oxygen (A)

On decomposition of water we get hydrogen and oxygen.

So, B is hydrogen

Pure water is a poor conductor of electricity and when acidified by adding sulphuric acid it can conduct electricity hence, C is water.

During electrolysis of water, hydrogen gas is evolved at cathode and oxygen gas is evolved at anode.

Since at D oxygen gas is evolved D is anode.