Topic A5 - Equilibria

Question 1

What is Le Chatelier’s Principle?

Answer 1

equilibrium shifts to counteract change imposed

Question 2

What are the conditions that change that cause equilibrium to shift?

Answer 2

-adding/ removing one of the substances
-changing the temperature
-changing the pressure

Question 3

Which way does the equilibrium shift if temperature increases?

Answer 3

shifts in direction of endothermic reaction (i.e. if forwards reaction is endothermic, equilibrium would shift right)

Question 4

Which direction does equilibrium shift if you add more reactants?

Answer 4

shifts to the right - as the forwards reaction uses up extra reactants

Question 5

What happens to the position of equilibrium if pressure increases?

Answer 5

equilibrium shifts to side with fewer moles of gas, as this brings down the pressure (i.e. fewer moles of gas on left, equilibrium shifts left)

Question 6

What is the only condition that affects Kc?

Answer 6

temperature

Question 7

What happens to Kc when temperature increases?

Answer 7

-equilibrium shifts in direction of endothermic reaction
-as endothermic reaction absorbs extra heat
Therefore, Kc increases

Question 8

What affect does changing concentrations and pressure have on Kc value?

Answer 8

no affect - Kc remains constant