Chemistry 5070/41 — May/June 2022

Cambridge O-Level · Alternative to Practical · worked solutions for every part, with the mark scheme

questions

marks

minutes

Topics Use of Techniques, Apparatus and Materials · Analysis, Conclusions and Evaluation · Experimental Contexts · Observations and Measurements · Qualitative Analysis · Planning Experiments and Investigations

Q111MUse of Techniques, Apparatus and MaterialsAnalysis, Conclusions and EvaluationObservations and MeasurementsExperimental ContextsFree sample

A student transfers $4.0\text{ cm}^3$ of aqueous potassium manganate(VII) from the burette into apparatus A.

Fig. 1.1

(a)

Name apparatus A.

______

(b)

The student adds $25\text{ cm}^3$ of dilute sulfuric acid to apparatus A.

Name a suitable piece of apparatus to measure the $25\text{ cm}^3$ of acid.

______

(c)

The student heats the mixture in apparatus A until it reaches $60^\circ\text{C}$ .

Name a suitable piece of apparatus to measure the temperature.

______

(d)

The student:

places apparatus A, containing the hot mixture, on a white tile
adds $10\text{ cm}^3$ of aqueous glucose to apparatus A
starts a stop-watch
stirs the contents of apparatus A and records the temperature
stops the stop-watch when the colour changes
records the time taken.

The student does this experiment at five different temperatures.

The results are shown in the table.

temperature / $^\circ\text{C}$	time taken / $\text{s}$
55	5
40	25
32	48
23	90
20	150

A grid to plot the results is shown.

Fig. 1.2

(i)

Label the axes on the grid. Include the appropriate units.

(ii)

Plot the results on the grid.

(iii)

Draw a curve of best fit.

(iv)

Use the graph to:

determine the time taken at $25^\circ\text{C}$
extend your curve of best fit to determine the temperature at which the reaction takes $180\text{ s}$
suggest why an experiment at $70^\circ\text{C}$ is not done.

time = ______ $\text{s}$
temperature = ______ $^\circ\text{C}$
suggestion ______

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4 more questions

Q2Experimental Contexts · Use of Techniques, Apparatus and Materials · Qualitative Analysis · Analysis, Conclusions and Evaluation16M
Q3Planning Experiments and Investigations · Use of Techniques, Apparatus and Materials8M
Q4Use of Techniques, Apparatus and Materials · Experimental Contexts · Analysis, Conclusions and Evaluation · Observations and Measurements · Qualitative Analysis18M
Q5Observations and Measurements · Experimental Contexts · Analysis, Conclusions and Evaluation7M

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