In the reaction $N_{2(g)} + 3H_{2(g)} \rightleftharpoons 2NH_{3(g)}; \Delta H = -93.6 \ kJ$,the yield of ammonia does not increase when:

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; $PCl_{5(g)} \rightleftharpoons PCl_{3(g)} + Cl_{2(g)}$,the forward reaction at constant temperature is not favoured by:

The rate of reaction of which of the following is not affected by pressure?

The equilibrium $2 Cu^{+} \rightleftharpoons Cu + Cu^{2+}$ in aqueous medium at $25^{\circ} C$ shifts towards the left in the presence of
$(A)$ $NO_3^{-}$ $(B)$ $Cl^{-}$ $(C)$ $SCN^{-}$ $(D)$ $CN^{-}$

The following gaseous reaction is taking place in a vessel: $C_2H_4(g) + H_2(g) \rightleftharpoons C_2H_6(g)$; $\Delta H = -32.7 \ kcal$. Which of the following will increase the equilibrium concentration of $C_2H_6$?