CIE Jun 2017 v2 Paper 4 Q2

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(a) Complete the table to show how both AgNO3(aq) and NH3(aq) could be used to distinguish between solutions of NaCl (aq) and NaI(aq). test performed observation with NaCl observation with NaI PMT Important information for this questionIn this question (pr) means a solution in propanone. Sodium iodide is soluble in propanone giving Na+(pr) and I(pr). Sodium chloride is insoluble in propanone. [2] The reaction between 2-chlorobutane and sodium iodide in propanone is shown. CH3CH2CHCl CH3(pr) + Na+(pr) + I(pr) CH3CH2CHICH3(pr) + NaCl (s) The rate of this reaction can be investigated by measuring the electrical conductivity of the reaction mixture. The electrical conductivity changes as the reaction progresses due to the precipitation of the NaCl produced. (b) (i) Suggest how the electrical conductivity will change as the reaction proceeds. Explain your answer.[1] (ii) Describe a suitable method for studying the rate of this reaction at a temperature of 40 C, using the following.an electrical conductance meter which measures the electrical conductivity of solutions solutions of known concentrations of 2-chlorobutane in propanone and sodium iodide in propanone stopclock access to standard laboratory equipment[3]UCLES 2017 9701/42/M/J/17<br /> PMT (c) The rate of this reaction was measured at different initial concentrations of the two reagents. The table shows the results obtained. experiment [CH3CH2CHCl CH3] / mol dm3 [I] / mol dm3 relative rate 1 2 3 4 0.06 0.10 0.06 0.08 0.03 0.03 0.05 0.04 3 5 5 to be calculated (i) Deduce the order of reaction with respect to each of [CH3CH2CHCl CH3] and [I]. Explain your reasoning. order with respect to [CH3CH2CHCl CH3]order with respect to [I][2] (ii) Write the rate equation for this reaction, stating the units of the rate constant, k. rate =mol dm3 s1 units of k =[1] (iii) Calculate the relative rate for experiment 4. relative rate for experiment 4 =[1]UCLES 2017 9701/42/M/J/17 [Turn over<br /> (d) (i) Suggest the mechanism for the reaction of 2-chlorobutane with iodide ions. Draw out the steps involved, including the following.all relevant lone pairs and dipoles curly arrows to show the movement of electron pairs the structure of any transition state or intermediate PMT (ii) This reaction was carried out using a single optical isomer of 2-chlorobutane. Use your mechanism in (i) to predict whether the product will be a single optical isomer or a mixture of two optical isomers. Explain your answer.[1] [3] (e) (i) State the number of peaks that would be seen in the carbon-13 NMR spectrum of CH3CH2CHCl CH3.[1] (ii) There are two isomers of CH3CH2CHCl CH3 that have fewer peaks in their carbon-13 NMR spectra than CH3CH2CHCl CH3. Draw the structures of the isomers and state the number of peaks for each isomer. isomer 1 isomer 2 number of peaks =number of peaks =[3] [Total: 18]UCLES 2017 9701/42/M/J/17<br /> PMT Question 3 starts on the next page.UCLES 2017 9701/42/M/J/17 [Turn over<br />

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