Stogs GCSE Interleaving Equilibria S

The equation shows a reversible reaction, where A to D are different gases. Which direction would be favoured if the pressure were increased?

• Forwards as more gas moles in products.

• Backwards as more gas moles in products.

• Forwards as more gas moles in reactants.

• Backwards as more gas moles in reactants.

Nitrogen for use in the Haber process is obtained from air.

• True

• False

How is ammonium removed during the Haber process?

• By adding gases that react with the hydrogen and nitrogen.

• By fractional distillation.

• By cooling to liquefy it.

Which of the following statements about equilibrium is true?

• At equilibrium, all the reactants have reacted to form products.

• At equilibrium, the amount of products equal the amount of reactants.

• At equilibrium, the rate of the forward reaction is equal to the rate of the backwards reaction.

• At equilibrium both the forwards and the backwards reactions stop.

In a reversible reaction the forward reaction is endothermic. What can you say about the enthalpy change for the reverse reaction?

• It is also endothermic.

• It is exothermic.

• It’s energy transfer is greater.

• It’s energy transfer is the same.

• It’s energy transfer is less.

Consider the Haber process. Would increasing the temperature increase or decrease the yield of product?

• Increase

• Decrease

Consider the Haber process. Would increasing the temperature increase or decrease the rate of reaction?

• Increase

• Decrease

What does Le Chatelier’s Principle say about the effect of changing the conditions of a reversible reaction at equilibrium?

• Changing conditions will lead to a greater product yield.

• If you change the conditions of a reversible reaction at equilibrium, the system will try to counteract that change.

• Changing conditions would lead to a lesser product yield.

• The reaction responds like a stroppy teenager.

Blue Cu²⁺ ions can react with Cl^- ions to form a yellow copper compound. Cu²⁺ + 4Cl^- ↔ [CuCl₄]^2-. The solution turned green. Why?

• The light made the blue appear green.

• Copper was oxidised to Cu³⁺ which is a green solution.

• At equilibrium both the yellow and blue solutions were present. The mixing of these two colours gave a green solution.

• Chemistry is a magical subject.

N₂O₄ is a colourless gas. NO₂ is a brown gas. Consider the equation: N₂O₄(g) ↔ 2NO₂(g). When a mixture of the gases is heated, the colour becomes darker brown. Is the forwards reaction exothermic or endothermic?

• Exothermic

• Endothermic