In which of the following equilibria does a change in the volume of the system not alter the number of moles?

In which of the following reactions will an increase in pressure lead to an increase in the yield of products?

Which of the following factors will favour the reverse reaction in a chemical equilibrium?

The equilibrium $2 Cu^{+} \rightleftharpoons Cu + Cu^{2+}$ in aqueous medium at $25^{\circ} C$ shifts towards the left in the presence of
$(A)$ $NO_3^{-}$ $(B)$ $Cl^{-}$ $(C)$ $SCN^{-}$ $(D)$ $CN^{-}$

Does the number of moles of reaction products increase,decrease,or remain the same when each of the following equilibria is subjected to a decrease in pressure by increasing the volume?
$(a) \quad PCl_{5(g)} \longleftrightarrow PCl_{3(g)} + Cl_{2(g)}$
$(b) \quad CaO_{(s)} + CO_{2(g)} \longleftrightarrow CaCO_{3(s)}$
$(c) \quad 3Fe_{(s)} + 4H_2O_{(g)} \longleftrightarrow Fe_3O_{4(s)} + 4H_{2(g)}$

In a reversible reaction at $300 \ K$,$K_c > K_p$ and $\Delta H = +40 \ kcal$. The product will be obtained in a higher amount on: