Distinguish between:

Gas and vapour.

Which one contains more heat energy and by how much? 

(i) $1 \mathrm{kg}$ of water at $373 \mathrm{K}$ (ii) $1 \mathrm{kg}$ of steam at $373 \mathrm{K}$ 

Which of the following will produce more severe burns, and why? 

(i) water at $373 \mathrm{K}$ (ii) steam at $373 \mathrm{K}$

In which state will water exist at 

(i) $-2 {}^0\mathrm{C}$

(ii) $50 {}^0\mathrm{C}$

(iii) $102 {}^0\mathrm{C}$

Explain.