Which of the following conditions is used to obtain atomic $Cl$ from molecular $Cl_2$?

On cooling the following system at equilibrium:
$CO_{2(s)} \rightleftharpoons CO_{2(g)}$

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 $C_2H_6$?

For the following reaction,which change will shift the equilibrium towards the product?
$I_{2(g)} \rightleftharpoons 2I_{(g)}; \Delta H_r^o(298 \ K) = +150 \ kJ$

Consider the reaction $HCN_{(aq)} \Leftrightarrow H_{(aq)}^{+} + CN_{(aq)}^{-}$. At equilibrium,the addition of $CN_{(aq)}^{-}$ would

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