The Total solution for NCERT class 6-12
One mole of an ideal gas at standard temperature and pressureoccupies 22.4 L (molar volume). What is the ratio of molar volume to the atomicvolume of a mole of hydrogen? (Take the size of hydrogen molecule to be about 1). Why is this ratio so large?
Radius of hydrogen atom, r =0.5 = 0.5 × 10–10 mVolumeof hydrogen atom =
Now, 1 mole of hydrogen contains 6.023 × 1023 hydrogenatoms.
∴ Volume of 1 mole of hydrogenatoms, Va = 6.023 × 1023 × 0.524 ×10–30
= 3.16 × 10–7 m3
Molar volume of 1 mole of hydrogen atoms at STP,
Vm =22.4 L = 22.4 × 10–3 m3
Hence, the molar volume is 7.08 × 104 times higherthan the atomic volume. For this reason, the inter-atomic separation inhydrogen gas is much larger than the size of a hydrogen atom.