This question is about reactions between gases.
When colourless hydrogen gas is heated with purple iodine vapour, they react to form colourless hydrogen iodide gas.
The equation for this reversible reaction is:
hydrogen+iodine⇌hydrogen iodide\text{hydrogen} + \text{iodine} \rightleftharpoons \text{hydrogen iodide}hydrogen+iodine⇌hydrogen iodide
This reversible reaction reaches equilibrium in a sealed container.
How does the equation show that the reaction is reversible?
Which two statements are correct when the reaction reaches equilibrium?
The initial mixture of hydrogen and iodine in the sealed container is deep purple. Hydrogen iodide is colourless.
How will the colour of the gas mixture in the sealed container have changed when equilibrium is reached?
The rate of reaction between gases is affected by changing the pressure.
Complete the sentences:
When the pressure of the reacting gases is increased, the rate of reaction ____________.
This is because at higher pressures the number of particles in a given volume ____________.
This means that the frequency of collisions ____________.
Give one other way of changing the rate of reaction between gases.
You should not refer to pressure in your answer.
Practise AQA GCSE Chemistry Reversible reactions and dynamic equilibrium with exam-style questions for Foundation and Higher tier. 30 questions covering Reversible reactions, Energy changes and reversible reactions, Equilibrium, The effect of changing conditions on equilibrium (HT only), The effect of changing concentration (HT only), The effect of temperature changes on equilibrium (HT only), and The effect of pressure changes on equilibrium (HT only), matched to the AQA GCSE Chemistry (8462) specification and written in Paper 1 and Paper 2 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.