Change in volume of the system does not alter the number of moles in which of the following equilibrium?

The equilibrium $Cr_2O_7^{2-} + H_2O \rightleftharpoons 2CrO_4^{2-} + 2H^{+}$ is shifted to the right in:

In which of the following reactions is the yield of the product favored by high pressure and high temperature?

Which of the following reactions will be affected by increasing the pressure? Also,mention whether the change will cause the reaction to proceed in the forward or backward direction.
$(i)$ $COCl_{2(g)} \longleftrightarrow CO_{(g)} + Cl_{2(g)}$
$(ii)$ $CH_{4(g)} + 2S_{2(g)} \longleftrightarrow CS_{2(g)} + 2H_2S_{(g)}$
$(iii)$ $CO_{2(g)} + C_{(s)} \longleftrightarrow 2CO_{(g)}$
$(iv)$ $2H_{2(g)} + CO_{(g)} \longleftrightarrow CH_3OH_{(g)}$
$(v)$ $CaCO_{3(s)} \longleftrightarrow CaO_{(s)} + CO_{2(g)}$
$(vi)$ $4NH_{3(g)} + 5O_{2(g)} \longleftrightarrow 4NO_{(g)} + 6H_2O_{(g)}$

The increase of pressure on the ice $\rightleftharpoons$ water system at constant temperature will lead to:

What happens when an inert gas is added to an equilibrium system while keeping the volume unchanged?