A reaction uses the same solution concentration at 20 °C and 35 °C. A student explains the faster reaction at 35 °C by saying particles are larger and the activation energy has decreased.
Evaluate the explanation.
[4 marks]AQA GCSE Chemistry June 2023 Paper 2H
5 questions on this paper's topics
23:001 of 5
A computer model displays 70 reactant particles and 30 product particles at equilibrium. During the next second 6 reactant particles change to product.
.1
Calculate the percentage of reactant particles that change to product in that second. Give your answer to at least two significant figures.
[2 marks].2
Predict the number changing back in the same second and explain why the display can stay at 70:30.
[2 marks]A sample contains very long covalent molecules. It softens when heated, does not conduct electricity and becomes solid again on cooling.
Explain these observations using a polymer model.
[6 marks]A beaker becomes colder when two substances react. A student sketches a reaction profile with products below reactants and no energy barrier.
Explain how the profile should be corrected and what each correction means.
[4 marks]A factory uses 240 tonnes of a finite mineral each year. Process improvements reduce annual use by 15%. A managed forest supplies a different raw material that can regrow.
.1
Calculate the factory’s new annual mineral use.
[2 marks].2
Explain why the mineral remains finite and why a renewable resource is not automatically sustainable.
[2 marks]