Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Unit
Physical Chemistry
442 practice questions
Topics covered
Practice questions
161–170 of 442
Question 161
1 mark · Easy
Answer and see the solution →Complete the sentence: Reactions between a solid and a liquid are faster when the solid has a ________ surface area.
Question 162
3 marks · Easy
Answer and see the solution →Iron filings (very small pieces) and an iron nail (large piece) are both placed separately into dilute sulfuric acid. The mass of each iron sample is the same.
(a)[1 mark]State which form of iron will react more quickly.
(b)[2 marks]Describe two reasons why the form you selected in (a) reacts faster.
Question 163
2 marks · Easy
Answer and see the solution →A reaction between a solid and a liquid produced 32 cm³ of gas in 4 minutes. When the same mass of solid is powdered and reacted in the same conditions, the reaction is complete in 2 minutes. Calculate the average rate of gas production in both cases. Give your answers in cm³/min and compare the results.
Question 164
2 marks · Normal
Answer and see the solution →A student reacts powdered calcium carbonate with dilute hydrochloric acid. Explain why the reaction happens faster than if the same mass of calcium carbonate is in large lumps, not powder.
Question 165
4 marks · Normal
Answer and see the solution →Solid magnesium ribbon reacts with dilute sulfuric acid to produce hydrogen gas. A student wants to investigate how changing the surface area of magnesium affects the rate of reaction.
(a)[1 mark]Describe a change the student could make to increase the surface area of magnesium used.
(b)[2 marks]Explain how this change affects the rate of the reaction.
(c)[1 mark]State one variable other than surface area that should be kept constant in this investigation.
Question 166
3 marks · Normal
Answer and see the solution →A student conducts two experiments: - Experiment 1: 5.0 g of marble chips (large lumps) - Experiment 2: 5.0 g marble powder Both react with identical volumes and concentrations of dilute hydrochloric acid at the same temperature. In Experiment 1, all the marble has reacted in 7 minutes. In Experiment 2, the reaction is complete in 2 minutes.
Calculate the average rate of reaction in grams of marble reacted per minute for: (a) Experiment 1 (b) Experiment 2.
Question 167
3 marks · Normal
Answer and see the solution →A factory grinds solid reactants used in a chemical process into fine powder instead of using large lumps. Explain, with reasons, how and why this affects the rate of the reaction.
Question 168
4 marks · Normal
Answer and see the solution →The table shows the total volume of gas produced over time when excess hydrochloric acid reacts separately with two forms of zinc of the same mass: powder and large granules.
Volume of gas produced (cm³) Time (min) Zinc powder (cm³) Zinc granules (cm³) 0 0 0 1 38 15 2 65 25 3 85 32 4 90 39 5 90 43 6 90 44 (a)[1 mark]Describe the difference in the rate of reaction between the powder and granules during the first 3 minutes.
(b)[1 mark]Give the total volume of gas produced at the end of both reactions.
(c)[1 mark]Explain why both forms of zinc produced the same final volume of gas.
(d)[1 mark]Explain why the reaction with zinc powder is faster.
Question 169
1 mark · Normal
Answer and check →Which change will increase the rate of a reaction between a solid and a liquid most effectively?
- A.Grinding the solid into a powder.
- B.Decreasing the temperature.
- C.Using less of the liquid.
- D.Stirring less frequently.
Question 170
2 marks · Normal
Answer and see the solution →State two factors, other than surface area, that can increase the rate of a reaction between a solid and a liquid.