Question

Which of the two has more heat $1\mathrm{g}$ water at ${100}^{\circ }\mathrm{C}$ or $1\mathrm{g}$ steam at ${100}^{\circ }\mathrm{C}$? Give reason.

Answer 1

1. Latent heat of vaporization: It is the amount of heat energy that is required to convert 1 kg of a liquid into a gas without any rise in temperature.
2. Steam gives out $22.5\times {10}^{5}J/Kg$ more heat than boiling water at the same temperature.
3. $1\mathrm{g}$ water at ${100}^{\circ }\mathrm{C}$ requires latent heat to convert into $1\mathrm{g}$ steam at ${100}^{\circ }\mathrm{C}$.
4. So $1\mathrm{g}$ steam at ${100}^{\circ }\mathrm{C}$ has more heat than $1\mathrm{g}$ water at ${100}^{\circ }\mathrm{C}$.