In the equilibrium $Ice \rightleftharpoons Water$,what happens when pressure is increased?

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?
$(a)$ $PCl_{5(g)} \rightleftharpoons PCl_{3(g)} + Cl_{2(g)}$
$(b)$ $CaO_{(s)} + CO_{2(g)} \rightleftharpoons CaCO_{3(s)}$
$(c)$ $3Fe_{(s)} + 4H_{2}O_{(g)} \rightleftharpoons Fe_{3}O_{4(s)} + 4H_{2(g)}$

The role of a catalyst in a reversible reaction is to

The equilibrium $SO_2Cl_{2(g)} \rightleftharpoons SO_{2(g)} + Cl_{2(g)}$ is attained at $25 ^\circ C$ in a closed container and an inert gas helium is introduced. Which of the following statements is correct?

When $NaNO_3$ is heated in a closed vessel,$O_2$ is liberated and $NaNO_2$ is left behind. At equilibrium,

Which of the following gaseous reactions is favoured by low pressure?