Ncert Exercises & Solutions

One mole of oxygen gas at STP is equal to ______

1. $6.022 \times 10^{23}$ molecules of oxygen

2. $6.022 \times 10^{23}$ atoms of oxygen

3. 16 g of oxygen

4. 32 g of oxygen

(a, d)

1 mole of O₂ gas at STP

= 6.022 \times 10^{23}

molecules of O₂ (Avogadro Number)=32g of O₂. Hence, 1 mole of oxygen gas is equal to molecular weight of oxygen as well as Avogadro number.