Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Unit
Physical Chemistry
442 practice questions
Topics covered
Practice questions
51–60 of 188 · Normal
Question 51
3 marks · Normal
Answer and see the solution →In an experiment, 0.60 g of carbon dioxide is collected in the first two minutes of the reaction between marble chips and hydrochloric acid.
Calculate the average rate of reaction in g/min during these two minutes. Show your working.
Question 52
3 marks · Normal
Answer and see the solution →Explain why the rate of the reaction between marble chips and hydrochloric acid is fastest at the start and slows down as the reaction continues. Refer to changes in concentration and particle collisions in your answer.
Question 53
4 marks · Normal
Answer and see the solution →Time / min Mass of CO2 lost / g 0 0.00 1 0.32 2 0.54 3 0.63 4 0.66 5 0.67 (a)[1 mark]Calculate the average rate of reaction between 0 and 2 minutes (give your answer in g/min).
(b)[1 mark]Calculate the average rate of reaction between 2 and 5 minutes (give your answer in g/min).
(c)[2 marks]State and explain the main trend in the rate of reaction as time increases.
Question 54
1 mark · Normal
Answer and check →What is a suitable method to measure the volume of carbon dioxide produced during the reaction between marble chips and hydrochloric acid?
- A.Collecting gas over water in a measuring cylinder
- B.Measuring the temperature change of the reaction
- C.Observing the colour change of the solution
- D.Recording the change in pH using a pH sensor
Question 55
2 marks · Normal
Answer and see the solution →State two safety precautions you should take when performing an experiment to measure the rate of reaction between marble chips and hydrochloric acid.
Question 56
4 marks · Normal
Answer and see the solution →(a)[2 marks]Draw a labelled diagram of the apparatus you could use to measure the loss of mass during the reaction between excess marble chips and dilute hydrochloric acid.
(b)[2 marks]Explain why cotton wool is placed in the neck of the flask during this experiment.
Question 57
2 marks · Normal
Answer and see the solution →Explain why not every collision between reactant particles in a chemical reaction leads to a reaction.
Question 58
4 marks · Normal
Answer and see the solution →A student adds excess powdered magnesium to dilute hydrochloric acid in a beaker. The mixture fizzes and gives off a gas.
(a)[1 mark]State the name of the gas produced in this reaction.
(b)[3 marks]Explain, using collision theory, why the reaction is faster at the start than near the end.
Question 59
3 marks · Normal
Answer and see the solution →A student investigates the reaction between sodium thiosulfate and hydrochloric acid at two different temperatures. The reaction is much faster at 45°C than at 25°C. Explain, using collision theory, why increasing the temperature increases the rate of this reaction.
Question 60
4 marks · Normal
Answer and see the solution →The graph below shows the concentration of hydrochloric acid over time during its reaction with excess calcium carbonate.
Concentration of hydrochloric acid vs time (a)[2 marks]Describe how the rate of reaction changes during the experiment.
(b)[2 marks]Explain the shape of the curve using collision theory.