What happens when pressure is increased on the equilibrium system $Ice \rightleftharpoons Water$?

In the reaction: $H_2S \rightleftharpoons 2H^{+} + S^{2-}$,when $NH_4OH$ is added,then

In which of the following reactions,increase in the volume at constant temperature does not affect the number of moles at equilibrium?

The standard state Gibbs free energy change for the given isomerization reaction $cis-2-pentene \rightleftharpoons trans-2-pentene$ is $-3.67 \ kJ/mol$ at $400 \ K$. If more $trans-2-pentene$ is added to the reaction vessel,then:

Dihydrogen gas is obtained from natural gas by partial oxidation with steam as per the following endothermic reaction:
$CH_{4(g)} + H_2O_{(g)} \rightleftharpoons CO_{(g)} + 3H_{2(g)}$
$(a)$ Write an expression for $K_p$ for the above reaction.
$(b)$ How will the values of $K_p$ and the composition of the equilibrium mixture be affected by:
$(i)$ increasing the pressure
$(ii)$ increasing the temperature
$(iii)$ using a catalyst?

The role of a catalyst in a reversible reaction is to