The diameter of the water vapour molecule is \(2 \times 10^{- 10} \text{ m} \) and the number of molecules per unit volume at STP is \(2 . 7 \times 10^{25} \text{ m}^{- 3} .\) The mean free path for a water molecule in water vapour at \(373~\text{K}\) is:
1. \(2 . 5 \times 10^{- 7} ~\text{m}\)
2. \(6 \times 10^{- 7} ~\text{m}\)
3. \(3 \times 10^{- 7}~\text{m}\)
4. \(4 \times 10^{- 7}~\text{m}\)
Subtopic: Mean Free Path |