Question

If the intermolecular forces vanish away, the volume occupied by the molecules contained in $4.5\text{kg}$ water at STP will be

• A. $5.6{\text{m}}^3$
• B. $4.5{\text{m}}^3$
• C. $11.2{\text{m}}^3$
• D. $5.6\text{litres}$

Answer 1

The correct option is A $5.6{\text{m}}^3$

When intermolecular force vanishes, the liquid is converted into vapours. Molecular mass of water vapour $=18\text{g}=18\times {10}^{-3}\text{kg}$
We know volume occupied by $1\text{mole}$ of water vapour at STP $=22.4\text{litres}$.
$=22.4\times {10}^{-3}{\text{m}}^3$
$\therefore$ $4.5\text{kg}$ occupies $=\frac{22.4\times {10}^{-3}}{18\times {10}^{-3}}\times 4.5=5.6{\text{m}}^3$