Question

For the process $H_{2}O\left(l\right)\to H_{2}O\left(g\right)$, at $T={100}^{\circ }$C and 1 atmosphere pressure, the correct choice is:

• A. $\Delta S_{system}>0$ and $\Delta S_{surrounding}>0$
• B. $\Delta S_{system}>0$ and $\Delta S_{surrounding}<0$
• C. $\Delta S_{system}<0$ and $\Delta S_{surrounding}>0$
• D. $\Delta S_{system}<0$ and $\Delta S_{surrounding}<0$

Answer 1

The correct option is B $\Delta S_{system}>0$ and $\Delta S_{surrounding}<0$

At 100${}^{\circ }$C and 1 atmosphere pressure $H_{2}O\left(l\right)\rightleftharpoons H_{2}O\left(g\right)$ is at equilibrium.

For equilibrium,

$\Delta S_{total}=0$ and

$\Delta S_{system}+\Delta S_{surrounding}=0$

$\therefore \Delta S_{system}>0$ and $\Delta S_{surrounding}<0$

Hence,option B is correct.