The equilibrium which remains unaffected by a change in pressure is:

The oxidation of $SO_2$ to $SO_3$ by $O_2$ is an exothermic reaction: $2SO_2(g) + O_2(g) \rightleftharpoons 2SO_3(g) + \text{Heat}$. The yield of $SO_3$ will increase if:

For the chemical reaction $3X_{(g)} + Y_{(g)} \to X_3Y_{(g)}$,the amount of $X_3Y$ at equilibrium is affected by

According to Le Chatelier's principle,an increase in the temperature of the following reaction will:
$N_2 + O_2 \rightleftharpoons 2NO - 43,200 \ kcal$

In a vessel,the following two systems are in simultaneous equilibrium: $PCl_{5(g)} \rightleftharpoons PCl_{3(g)} + Cl_{2(g)}$ and $COCl_{2(g)} \rightleftharpoons CO_{(g)} + Cl_{2(g)}$. If some $CO$ is added to the vessel at constant volume,then at the new equilibrium:

The equation for the reaction in the figure below is: $H_{2(g)} + I_{2(g)} + \text{heat} \rightleftharpoons 2HI_{(g)}$
At the instant $3 \text{ min}$,what change was imposed on the equilibrium?