Formation of $SO_3$ takes place according to the reaction:
$2SO_2(g) + O_2(g) \rightleftharpoons 2SO_3(g); \,\, \Delta H = -45.2 \, kcal$
Which of the following factors favours the formation of $SO_3$?

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

$(a)$ What is required in chemical synthesis? What will be done for that?
$(b)$ Write Le Chatelier's principle.

The equilibrium of the reaction $2A_{(s)} + 3B_{(g)} \rightleftharpoons 3C_{(g)} + D_{(g)} + Q$ is represented as shown. If the pressure on the system is reduced to half of its original value,then:

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

Consider the following reaction where the enthalpy change is positive: $2A_{(g)} \rightleftharpoons C_{(g)} + D_{(g)}$. Which of the following will not affect the equilibrium?