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

The entropy change for the expansion of $2 \, \text{mol}$ of an ideal gas from $2 \, \text{L}$ to $20 \, \text{L}$ at a temperature of $27 \, ^oC$ is ...... $(R = 2 \, \text{cal/mol K})$

In a spontaneous process,the entropy of the system and its surroundings

At $373 \, K$,steam and water are in equilibrium and $\Delta H = 39.2 \, kJ \, mol^{-1}$. What will be $\Delta S$ for the conversion of $1 \, mole$ of water into steam?
$H_2O_{(l)} \to H_2O_{(g)}$ ... $J \, K^{-1} \, mol^{-1}$

In which of the following reactions is $\Delta S$ positive?

Given that $\Delta H = 0$ for the mixing of two gases,explain whether the diffusion of these gases into each other in a closed container is a spontaneous process or not?