Find out the direction the equilibrium will shift when pressure and temperature changes

For the following equations, tell in which directions, left or right , the equilibrium will shift when these changes are made: the temperature is increased, the pressure is increased by decreasing the volume of the reaction vessel, and a catalyst is added.

a.  3O2(g) + 271 kJ ----> <-----(the arrows go under/over each other) 2O3(g)

 

b. CH4(g) + Cl2(g) ----> <-----(the arrows go under/over each other) CH3Cl(g) + HCl(g) + 110 kJ

 

c. 2NO(g) + 2H2(g) ----><-----(the arrows go under/over each other) N2(g) + 2H2O(g) + 665kJ 

 

to answer part a ,use the fact that for an endothermic reaction if temperature is increased then amount of products are increased , so equilibrium will shift to the product side

if the pressure is increased the reaction shifts in the direction of fewer number of moles, so reactant moles are 4 in totaland products are 2 , so equilibrium will shift to product side.

catalyst has no effect on equilibirum , it will not shift equilibrium in any direaction it will just increase the rate of reaction

 

for part b and c , be careful that it is an exothermic reactions rather than endo , so amount of product are increased at equilibrium by a decrease in temperature