In which of the following processes is the maximum increase in entropy observed?

Identify the reaction/process in which the entropy increases.

$A$ heat engine is operating between $500 \ K$ and $400 \ K$. If the engine absorbs $100 \ J$ of heat,which of the following is an impossible amount of heat rejected by the engine (in $J$)?

Which one of the following has $\Delta S^o$ greater than zero?

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

Standard entropies of $X_2, Y_2$ and $XY_5$ are $70, 50$ and $110 \ J \ K^{-1} \ mol^{-1}$ respectively. The temperature in Kelvin at which the reaction $\frac{1}{2} X_2 + \frac{5}{2} Y_2 \rightarrow XY_5$ with $\Delta H = -35 \ kJ \ mol^{-1}$ will be at equilibrium is . . . . . . (Nearest integer).