## Chemistry (4th Edition)

1. Write the equilibrium constant expression: - The exponent of each concentration is equal to its balance coefficient. $$K_c = \frac{[Products]}{[Reactants]} = \frac{[ AB ]^{ 2 }}{[ A_2 ][ B_2 ]}$$ 2. At T1: $$K_c = \frac{(5)^2}{(1)(2)} = 12.5$$ 3. At T2: $$K_c = \frac{(3)^2}{(2)(3)} = 1.5$$ When temperature increased, $K_c$ decreased, so the equilibrium shifted to the left: The reaction is exothermic.