$A$ 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 $J$)?

What is entropy? Explain its role in spontaneity.

The entropy values (in $J K^{-1} mol^{-1}$) of $H_{2(g)} = 130.6$,$Cl_{2(g)} = 223.0$ and $HCl_{(g)} = 186.7$ at $298 \ K$ and $1 \ atm$ pressure. Then entropy change for the reaction $H_{2(g)} + Cl_{2(g)} \to 2HCl_{(g)}$ is :-

Entropy is maximum in case of

For a reversible expansion of $5 \, \text{mol}$ of an ideal gas at $27 \, ^\circ\text{C}$ from a volume of $8 \, \text{dm}^3$ to $80 \, \text{dm}^3$,the change in entropy is ...... $J \, K^{-1}$.

What will be $\Delta S$ for the reaction: $2A + 3B \to 4C + 5D$ (in $J \ K^{-1}$)?
Given:
$\Delta S_A^o = 100 \ J \ mol^{-1} \ K^{-1}$
$\Delta S_B^o = 120 \ J \ mol^{-1} \ K^{-1}$
$\Delta S_C^o = 200 \ J \ mol^{-1} \ K^{-1}$
$\Delta S_D^o = 150 \ J \ mol^{-1} \ K^{-1}$