Which condition is more favorable for the melting of ice?

In which of the following systems will doubling the volume of the container cause a shift to the right?

In the gaseous equilibrium $H_2X_2 + \text{heat} \rightleftharpoons 2HX$,the formation of $HX$ will be favoured by

The equilibrium constant for a reaction,$A + B \rightleftharpoons C + D$ is $1 \times 10^{-2}$ at $298 \ K$ and is $2$ at $273 \ K$. The chemical process resulting in the formation of $C$ and $D$ is

In a reversible reaction,a catalyst:

In the following system,$PCl_{5(g)} \rightleftharpoons PCl_{3(g)} + Cl_{2(g)}$ at equilibrium,upon addition of xenon gas at constant $T$ & $p$,the concentration of