A sample of 0.1 g of water at $100^{\circ} \mathrm{C}$ and normal pressure ( $1.013 imes 10^{5} \m

Question

A sample of 0.1 g of water at $100^{\circ} \mathrm{C}$ and normal pressure ( $1.013 	imes 10^{5} \mathrm{~N} \mathrm{~m}^{-2}$ ) requires 54 cal of heat energy to convert to steam at $100^{\circ} \mathrm{C}$. If the volume of the steam produced is 167.1 cc , the change in internal energy of the sample, is\

Professor PC Thomas Classes · Answer

(b) : Using first law of thermodynamics,\ $\Delta Q=\Delta U+\Delta W$\ $\Rightarrow \quad 54 	imes 4.18=\Delta U+1.013 	imes 10^{5}\left(167.1 	imes 10^{-6}-0ight)$\ $\Rightarrow \quad \Delta U=208.7 \mathrm{~J}$