Which of the following is zero during the adiabatic expansion of a gas?

At $1 \ atm$ pressure,if $\Delta S_{\text{vap}} = 75 \ J \ K^{-1} \ mol^{-1}$ and $\Delta H_{\text{vap}} = 30 \ kJ \ mol^{-1}$,what will be the boiling point of the liquid in $K$?

The entropy change for the conversion of $1 \, \text{mol}$ of liquid water to steam at $373 \, K$ is ...... $J/K$ (Given: $\Delta H_{\text{vap}} = 2.257 \, kJ/g$). (in $0.9$)

What is entropy?

For the reactions,
$2 Cl_{(g)} \longrightarrow Cl_{2(g)}$
$CO_{2(g)} \longrightarrow CO_{(g)} + \frac{1}{2} O_{2(g)}$
What are the signs of $\Delta S$, respectively?

Which of the following is correct regarding entropy?