Head to savemyexams.com for more awesome resources Chemical Change & Rate of Reaction 6.1 Chemical Change & Rate of Reaction Question Paper Course CIE IGCSE Chemistry Section 6. Chemical Reactions Topic 6.1 Chemical Change & Rate of Reaction Difficulty Easy Time allowed: 40 Score: /33 Percentage: /100 Page 1 of 9 © 2015-2023 Save My Exams, Ltd. · Revision Notes, Topic Questions, Past Papers Head to savemyexams.com for more awesome resources Question 1a An organic compound decomposes to form nitrogen. C6H5N2Cl(aq) → C6H5Cl(l) + N2(g) Explain the state symbols. aq ................................................................... l ................................................................... g ................................................................... [2 marks] Question 1b Draw a diagram to show the arrangement of the outer electrons in one molecule of nitrogen. [2 marks] Page 2 of 9 © 2015-2023 Save My Exams, Ltd. · Revision Notes, Topic Questions, Past Papers Head to savemyexams.com for more awesome resources Question 1c The rate of this reaction can be measured using the following apparatus. The results of this experiment are shown on the graph below. i) How does the rate of this reaction vary with time? [1] ii) Why does the rate vary? iii) The reaction is catalysed by copper powder. Sketch the graph for the catalysed reaction on the same grid. iv) Why is copper powder more effective as a catalyst than a single piece of copper? [2] [2] [1] [6 marks] Page 3 of 9 © 2015-2023 Save My Exams, Ltd. · Revision Notes, Topic Questions, Past Papers Head to savemyexams.com for more awesome resources Question 2a Biological catalysts produced by microbes cause food to deteriorate and decay. i) What is the name of these biological catalysts? [1] ii) Freezing does not kill the microbes. Suggest why freezing is still a very effective way of preserving food. [2] [3 marks] Question 2b Describe how the pea plant makes a sugar such as glucose. [3 marks] Page 4 of 9 © 2015-2023 Save My Exams, Ltd. · Revision Notes, Topic Questions, Past Papers Head to savemyexams.com for more awesome resources Question 3a A student investigates the reaction of small pieces of zinc with dilute sulfuric acid at 20 °C. The zinc is in excess. The graph shows the volume of hydrogen gas released as the reaction proceeds. Suggest why the volume of hydrogen gas stays the same after 10 minutes. [1 mark] Question 3b Deduce the time taken from the start of the experiment to collect 20 cm3 of hydrogen gas. [1 mark] Question 3c The student repeats the experiment at 30 °C. All other conditions stay the same. Draw a line on the grid in part (a) to show how the volume of hydrogen gas changes with time when the reaction is carried out at 30 °C. [2 marks] Page 5 of 9 © 2015-2023 Save My Exams, Ltd. · Revision Notes, Topic Questions, Past Papers Head to savemyexams.com for more awesome resources Question 3d The student repeats the experiment using zinc powder instead of small pieces of zinc. Describe how the rate of reaction differs when zinc powder is used. Give a reason for your answer. [2 marks] Question 4a Acids have characteristic properties. The rate of reaction of iron with sulfuric acid can be determined by measuring the time taken to produce 20cm3 of hydrogen. A student measured the time taken to produce 20 cm3 of hydrogen using three different concentrations of sulfuric acid. In each experiment the student used: 1g of iron powder the same temperature the same volume of sulfuric acid. The results are shown in the table. concentration of acid in mol / dm3 0.1 0.2 0.5 time /s 33 17 8 Use the information in the table to describe how the rate of reaction changes with the concentration of sulfuric acid. [1 mark] Page 6 of 9 © 2015-2023 Save My Exams, Ltd. · Revision Notes, Topic Questions, Past Papers Head to savemyexams.com for more awesome resources Question 4b Describe the effect of each of the following on the rate of this reaction with 0.5 mol / dm3 of sulfuric acid. Larger pieces of iron are used. All other conditions stay the same. ................................................................................................................... The temperature is increased. All other conditions stay the same. ................................................................................................................... [2 marks] Question 5 Sulfur dioxide is a pollutant in the air. Sulfur dioxide is oxidised to sulfur trioxide in the air. Oxides of nitrogen act as catalysts for this reaction. What is meant by the term catalyst? [1 mark] Question 6a A student investigates the rate of reaction of large pieces of magnesium carbonate with an excess of dilute nitric acid. MgCO3 + 2HNO3 → Mg(NO3)2 + CO2 + H2O Name the salt formed when magnesium carbonate reacts with dilute nitric acid. [1 mark] Page 7 of 9 © 2015-2023 Save My Exams, Ltd. · Revision Notes, Topic Questions, Past Papers Head to savemyexams.com for more awesome resources Question 6b The graph shows how the volume of carbon dioxide changes with time. After how many seconds did the reaction finish? [1 mark] Question 6c From the graph, deduce the volume of carbon dioxide produced during the first 50 seconds of the experiment. [1 mark] Question 6d The experiment is repeated using smaller pieces of the same mass of magnesium carbonate. All other conditions are kept the same. Draw a line on the grid for the experiment using smaller pieces of magnesium carbonate. [2 marks] Page 8 of 9 © 2015-2023 Save My Exams, Ltd. · Revision Notes, Topic Questions, Past Papers Head to savemyexams.com for more awesome resources Question 6e How does increasing the temperature affect the rate of this reaction? All other conditions are kept the same. [1 mark] Question 6f How does decreasing the concentration of nitric acid affect the rate of this reaction? All other conditions are kept the same. [1 mark] Page 9 of 9 © 2015-2023 Save My Exams, Ltd. · Revision Notes, Topic Questions, Past Papers
