Question

Assertion (A): Under identical conditions, 1 L of O₂ gas and 1 L of O₃ gas contain the same number of oxygen atoms.

Reason (R): 1 L of O₂ and 1 L of O₃ contain the same number of moles under identical conditions.

Options

• If both A and R are true, and R is the correct explanation of A.

• If both A and R are true, but R is not the correct explanation of A.

• If A is true, but R is false.

• If both A and R are false.

Answer 1

If both A and R are true, but R is not the correct explanation of A.

Explanation:

The assertion is true because while 1 L of O₂ and 1 L of O₃ contain the same number of molecules (by Avogadro’s law), they break down into different numbers of individual oxygen atoms due to their atomicity one mole of O₂ yields 2 moles of atoms, while one mole of O₃ yields 3 moles of atoms. The reason is also true because equal volumes of all gases under identical conditions of temperature and pressure contain the same number of moles. However, R is not the correct explanation for A because equal moles actually means the two samples have a different total number of oxygen atoms.