Question

Assertion (A): One litre of hydrogen weighs the same as one litre of oxygen.

Reason (R): One litre of hydrogen contains the same number of molecules as one litre of oxygen.

Options

• Both A and R are true and R is the correct explanation of A.

• Both A and R are true but R is not the correct explanation of A.

• A is true but R is false.

• A is false but R is true.

Answer 1

A is false but R is true.

Explanation:

By Avogadro’s law, equal volumes of gases at the same temperature and pressure contain equal numbers of molecules, so R is true. The molecules of oxygen are heavier than those of hydrogen, so equal volumes do not have equal masses; A is false.