What is the effect of halving the pressure by doubling the volume on the following system at $500\,^{\circ}C$?
$H_{2(g)} + I_{2(g)} \rightleftharpoons 2HI_{(g)}$

The equilibrium $2SO_{2(g)} + O_{2(g)} \rightleftharpoons 2SO_{3(g)}$ shifts forward,if

Aqueous solution of ferric nitrate when mixed with aqueous solution of potassium thiocyanate gives a red coloured solution. The intensity of the red colour becomes constant upon attaining equilibrium. Choose the correct statement when the following chemicals are added to the above solution at equilibrium:
$I$. Oxalic acid
$II$. Mercuric chloride

For the reaction $CO_{(g)} + H_2O_{(g)} \rightleftharpoons CO_{2(g)} + H_{2(g)}$ at a given temperature,the equilibrium amount of $CO_{2(g)}$ can be increased by

Explain the effect of concentration on equilibrium when two drops of $0.2 \ M$ potassium thiocyanate $(KSCN)$ are added to $1 \ mL$ of $0.2 \ M$ iron $(III)$ nitrate solution.

In the manufacture of $NH_3$ by Haber's process,the condition which would give maximum yield is $N_2(g) + 3H_2(g) \rightleftharpoons 2NH_3(g) + Q \ kcal$.