Photo AI
This question is about equilibrium - AQA - GCSE Chemistry Combined Science - Question 7 - 2020 - Paper 2
Question 7
This question is about equilibrium. 07.1 Describe how a reaction reaches equilibrium. Nitrogen dioxide gas reacts to form dinitrogen tetroxide gas. The reaction i... show full transcript
Worked Solution & Example Answer:This question is about equilibrium - AQA - GCSE Chemistry Combined Science - Question 7 - 2020 - Paper 2
Step 1
Describe how a reaction reaches equilibrium.
Answer
A reaction reaches equilibrium when it occurs in a sealed system that prevents the escape of reactants and products. At this point, the rate of the forward reaction and the rate of the reverse reaction are equal, resulting in no overall change in the concentration of reactants and products.
Step 2
Explain the effect on the equilibrium position of increasing the pressure.
Answer
As pressure increases, the equilibrium position shifts to the right-hand side. This occurs because the reaction produces fewer moles of dinitrogen tetroxide (N₂O₄) than the number of moles of nitrogen dioxide (NO₂) on the left-hand side.
Step 3
Explain the effect on the equilibrium position of increasing the temperature.
Answer
As temperature increases, the equilibrium position shifts to the left-hand side. This is because the forward reaction is exothermic, and raising the temperature drives the endothermic backward reaction, thus increasing the percentage of reactants (N₂O₄) in the mixture.