The newest 12 of 12 written questions. Open one to see it on the real paper.
Use your graph to predict the reaction time for 6 spatulas of sodium hydrogencarbonate. Show your working on the graph.
See it on the paper →Suggest why it is difficult to measure the reaction time accurately.
See it on the paper →The student repeats the measurement for each number of spatulas of sodium hydrogencarbonate. Suggest how repeating the measurements allows the student to evaluate the quality of the data.
See it on the paper →Suggest a change to step 2 to improve the procedure.
See it on the paper →The rate of reaction is calculated using the equation shown. rate = mass of sodium carbonate reaction time Calculate the rate of reaction when 2.0 g of sodium carbonate is used. Give your answer to two significant figures. rate of reaction = g / s
See it on the paper →On the grid, plot a graph of the temperature when first crystals of Q appear (vertical axis) against the mass of Q in solution.
See it on the paper →Draw the curve of best-fit.
See it on the paper →The rate of this reaction is calculated using the equation shown. rate = volume of gas collected 20 Calculate the rate of reaction in each experiment. rate of reaction with zinc powder only = cm 3 / s rate of reaction with zinc powder and iron powder = cm 3 / s
See it on the paper →Identify which experiment has the fastest rate of reaction. Explain your answer.
See it on the paper →Use your graph to determine the time it takes for a 1 cm piece of magnesium ribbon to fully react with 1.8 M hydrochloric acid. time = s
See it on the paper →The student repeats the experiment in (b). The student uses the same concentrations of hydrochloric acid at a temperature of 50 °C instead of room temperature. Everything else is kept the same. The student finds the reactions happen more quickly. On the grid in (b)(ii), draw the best-fit line you would expect to get at...
See it on the paper →The student thinks that one of the initial temperature readings is anomalous. Suggest which temperature reading is anomalous.
See it on the paper →Candidates generally calculated the rate of reaction correctly. Only stronger candidates correctly expressed their answers to two significant figures.
— Examiner report, October/November 2022, 0653/62 Q3(c)(iv) (Cambridge)
Many candidates labelled the axes with temperature on the vertical axis and mass on the horizontal axis, though a significant number omitted to put units with the labels. Most candidates chose simple scales that covered most of the grid and as a result they were able to plot the points correctly.
— Examiner report, May/June 2022, 0653/62 Q2(c)(i) (Cambridge)
Several candidates drew straight lines rather than a curve. Those attempting a curve, often joined points dot-to-dot, or neglected to draw a continuous smooth curve.
— Examiner report, May/June 2022, 0653/62 Q2(c)(ii) (Cambridge)
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