The role of a catalyst in a reversible reaction is to

What happens when a saturated solution of $CO_2$ is heated?

What will be the effect of pressure on the equilibrium reaction $C_{(s)} + H_2O_{(g)} \rightleftharpoons H_{2_{(g)}} + CO_{(g)}$?

In which of the following reactions will an increase in pressure lead to an increase in the yield of products?

The exothermic formation of $ClF_3$ is represented by the equation $Cl_{2(g)} + 3F_{2(g)} \rightleftharpoons 2ClF_{3(g)}$; $\Delta H = -329 \ kJ$. Which of the following will increase the quantity of $ClF_3$ in an equilibrium mixture of $Cl_2, F_2$ and $ClF_3$?

When $I_2$ dissociates to its atomic form the following reaction occurs:
$I_{2(g)} \rightleftharpoons 2I_{(g)} ; \Delta_r H^o = +150 \ kJ \ mol^{-1}$
The forward reaction is favoured at: