Which of the following reactions exhibits a decrease in entropy?

Calculate the entropy change of the surrounding if $2 \ moles$ of $H_2$ and $1 \ mole$ of $O_2$ gas combine to form $2 \ moles$ of liquid water by releasing $525 \ kJ$ of heat to the surrounding at constant pressure and at $300 \ K$. (in $J \ K^{-1}$)

One mole of an ideal gas at $350 \, K$ is in a $2.0 \, L$ vessel with thermally conducting walls,which are in contact with the surroundings. It undergoes isothermal expansion from $2.0 \, L$ to $3.0 \, L$ against a constant external pressure of $4 \, atm$. The change in entropy of the surroundings $(\Delta S_{surr})$ is $...... \, J \, K^{-1}$ (Nearest integer). Given: $R = 8.314 \, J \, K^{-1} \, mol^{-1}$.

The enthalpy of fusion of water is $6.01 \, kJ \, mol^{-1}$. The entropy change of $1 \, mole$ of ice at its melting point will be.....$J \, K^{-1} \, mol^{-1}$.

Direct conversion of $A$ to $B$ is difficult,so it is carried out by the path shown below. If $e.u.$ is the entropy unit,what will be $\Delta S_{(A \rightarrow B)}$?
Given:
$\Delta S_{(A \rightarrow C)} = 50 \ e.u.$
$\Delta S_{(C \rightarrow D)} = 30 \ e.u.$
$\Delta S_{(B \rightarrow D)} = 20 \ e.u.$

The enthalpy change for the transition of liquid water to steam at $100\,^oC$ is $40.8\, kJ\, mol^{-1}$. The entropy change for this process is .... $J\, K^{-1}\, mol^{-1}$.