Le Chatelier's principle is applicable to which of the following?

$aA \rightleftharpoons mB + nC$,$\Delta H = + x \ kcal$. If $m + n < a$,then conditions favouring forward reaction will be

The equilibrium constant for a reaction $A + B \rightleftharpoons C + D$ is $1 \times 10^{-3}$ at $298 \ K$ and is $2$ at $273 \ K$. The chemical reaction resulting in the formation of $C$ and $D$ is

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

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

For the reaction $2X_{(g)} + Y_{(g)} \rightleftharpoons 2Z_{(g)} + 80 \ kcal$,which conditions of temperature and pressure will yield more $Z$ at equilibrium?