click below
click below
Normal Size Small Size show me how
Equilibria
AQA A Level Chemistry
Question | Answer |
---|---|
Define a dynamic equilibrium. | An reversible reaction in a closed system where both the forward and reverse reaction have the same rate. The concentration of reactants and products remains the same |
What is Le Chatliers principle | The system will oppose any changes by minimising those changes |
What effect does a catalyst have on the equilibrium position? | No effect on equilibrium position. Both Forward and reverse reaction rate increased equally |
What would happen to the position of equilibrium if the concentration of the reactants increased? | Equilibrium will shift to the RHS |
How does the position of equilibrium change if you increase pressure | shifts to the side with less gaseous molecules |
How would a temperature increase affect a reversible reaction where the forward reaction is exothermic? | A shift in equilibrium towards the reactants LHS as it reduces the temperature |
Write the Kc expression for the following reaction X + Y ⇌ Z | Kc= [Z]/ [X] [Y] |
What are the units for Kc for the following reaction X + Y ⇌ Z | Mol-1dm3 |
What is the expression of Kc for this reaction? A + 2B ⇌ 2C+ D | kc =[A][B]²/[C]²[D] |
What are the units for Kc for this reaction? A + 2B ⇌ 2C+ D | no units |
What are the units for Kc for this reaction? A + 2B ⇌ 2C | mol dm⁻³ |
Kc for a reaction is 0.01 mol dm⁻³. To what side does the equilibrium lie for this reaction? | Towards the LHS more reactants than products in the equilibrium mixture |
Kc for a reaction is 3.23 mol dm⁻³. To what side does the equilibrium lie for this reaction? | Towards the RHS more products than reactants in the equilibrium mixture |
Is Kc affected by change in pressure | Kc is unaffected |
What happens to Kc if the temperature is increased for a reaction that’s exothermic in the forward direction | Kc will decrease |
What happens to Kc if the temperature is increased for a reaction that’s endothermic in the forward direction | Kc will increase |
Is Kc affected by a change in temperature | yes |