C5.3.3 - Choosing reaction conditions

Question 1

What is equilibrium yield?

Answer 1

The amount of desired product present in a reaction at equilibrium

Question 2

What does equilibrium yield depend upon?

Answer 2

• the temperature
• the concentration of the reactants
• the pressure

Question 3

What is Le Chatelier’s Principle?

Answer 3

Any change made to a reaction in equilibrium will result in the equilibrium position moving to minimise the change made

Question 4

Why is high pressure hard to obtain for chemical reactions?

Answer 4

High pressures need expensive equipment to compress gases, a lot of energy to run, and tough reactions vessels to withstand the pressure

Question 5

How do you choose a suitable temperature?

Answer 5

Chemical engineers choose a compromise temperature: which is low enough to achieve reasonable equilibrium yield but high enough to achieve a reasonable rate of reaction