The yield of the products in the reaction, $A_{2}(g)+2 B(g) \rightleftharpoons C(g)+Q$ kJ would be higher at

$A_{2}(g)+2 B(g) \rightleftharpoons C(g)+Q k J$ Obviously, the forward reaction is exothermic. Thus, according to Le-Chatelier's principle, the lower is temperature, greater would be the yield of ammonia. Also, the forward reaction occurs with decrease in number of gaseous molecules. Thus, according to Le-Chatelier's principle an increase in pressure, will shift the equilibrium in a direction in which the number of gaseous molecules decreases. In other words high pressure will favour the formation of products.