A student does an experiment to convert magnesium into magnesium oxide, $\text{MgO}$. A $0.36\text{ g}$ sample of magnesium is heated strongly for several minutes using the apparatus shown. (a) Name apparatus A and B . A \_\_\_\_\_\_ B \_\_\_\_\_\_ (b) Magnesium is converted into a white powder, $\text{MgO}$. The expected mass of $\text{MgO}$ is $0.60\text{ g}$. The student found that $0.55\text{ g}$ of $\text{MgO}$ is produced in the experiment. Suggest one reason why the…

Chemistry 5070/41 — May/June 2017

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

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

Q17MUse of Techniques, Apparatus and MaterialsAnalysis, Conclusions and EvaluationFree sample

A student does an experiment to convert magnesium into magnesium oxide, $\text{MgO}$ .

A $0.36\text{ g}$ sample of magnesium is heated strongly for several minutes using the apparatus shown.

Fig. 1.1

(a)

Name apparatus A and B.

A ______
B ______

(b)

Magnesium is converted into a white powder, $\text{MgO}$ . The expected mass of $\text{MgO}$ is $0.60\text{ g}$ .

The student found that $0.55\text{ g}$ of $\text{MgO}$ is produced in the experiment.

Suggest one reason why the mass of $\text{MgO}$ is lower than expected and suggest how the expected result may be achieved.

______

(c)

The student does a similar experiment using $0.36\text{ g}$ of zinc instead of $0.36\text{ g}$ of magnesium.

Explain why he is wrong to expect that the mass of zinc oxide will also be $0.60\text{ g}$ .
[ $A_r$ : $\text{Mg}, 24$ ; $\text{Zn}, 65$ ]

______

(d)

Suggest a safety item that the student should use when doing this experiment.

______

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5 more questions

Q2Planning Experiments and Investigations · Experimental Contexts5M
Q3Use of Techniques, Apparatus and Materials · Experimental Contexts9M
Q4Observations and Measurements · Experimental Contexts · Qualitative Analysis · Use of Techniques, Apparatus and Materials · Analysis, Conclusions and Evaluation17M
Q5Analysis, Conclusions and Evaluation · Qualitative Analysis8M
Q6Experimental Contexts · Observations and Measurements · Analysis, Conclusions and Evaluation14M

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