Chemistry 5070/41 — May/June 2013

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

questions

marks

minutes

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

Q17MUse of Techniques, Apparatus and MaterialsQualitative AnalysisObservations and MeasurementsExperimental ContextsAnalysis, Conclusions and EvaluationFree sample

A student heats some sodium hydrogencarbonate in the apparatus shown below. The reaction produces carbon dioxide.

2\text{NaHCO}_3 \rightarrow \text{Na}_2\text{CO}_3 + \text{CO}_2 + \text{H}_2\text{O}

Fig. 1.1

(a)

Name apparatus A.

______

(b)

Give a test for carbon dioxide.

______

(c)

The diagram below shows apparatus A at the completion of the reaction. The carbon dioxide collected is at room temperature and pressure.

Fig. 1.2

What volume of carbon dioxide is collected?

______ $\text{cm}^3$

(d)

Using your answer to (c), calculate the number of moles of carbon dioxide collected, measured at room temperature and pressure.
(One mole of a gas occupies $24\,000\text{ cm}^3$ at room temperature and pressure.)

______ moles

(e)

(i)

Using the equation for the reaction and your answer to (d) calculate the number of moles of sodium hydrogencarbonate used in the experiment.

______ moles

(ii)

Calculate the relative formula mass of sodium hydrogencarbonate.
[ $A_r$ : H, 1; C, 12; O, 16; Na, 23]

______

(iii)

Using your answers to (e)(i) and (e)(ii) calculate the mass of sodium hydrogencarbonate used in the experiment.

______ $\text{g}$

The rest of this paper

9 more questions

Q2Qualitative Analysis9M
Q3Experimental Contexts1M
Q4Experimental Contexts1M
Q5Experimental Contexts1M
Q6Analysis, Conclusions and Evaluation1M
Q7Analysis, Conclusions and Evaluation1M
Q8Observations and Measurements · Experimental Contexts · Analysis, Conclusions and Evaluation · Qualitative Analysis17M
Q9Experimental Contexts · Qualitative Analysis9M
Q10Experimental Contexts · Observations and Measurements · Analysis, Conclusions and Evaluation13M

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