OCR A Jan 2011 Paper 2 Q6

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6 Mass spectrometry and infrared spectroscopy are used in analysis. (a) The mass spectrum of compound Z is shown below. 18 relative abundance (%) 100 80 60 40 20 0 20 30 40 m / z 50 60 Compound Z has the molecular formula C3H6Ox. (i) Using the mass spectrum, deduce the value of x in C3H6Ox. Explain your answer.[2] (ii) Suggest a possible structure for Z. (iii) Suggest the formula of an ion that gives rise to the peak at m/z = 29 in this spectrum.[1] [1] (b) A space probe has detected the presence of the element iron on the surface of the planet Mars. Outline how a mass spectrum would show the presence of iron.[1]OCR 2011<br />
 (c) The space probe also detected different isotopes of sulfur on Mars. 19 (i) Outline how the mass spectrum would show how many different isotopes of sulfur were present on Mars.[1] (ii) The relative atomic mass of the sulfur found by the space probe was different from the relative atomic mass of sulfur on Earth. Suggest why.[1] (d) An environmental chemist used infrared spectroscopy to monitor air pollution outside a petrol station. The infrared spectrum below was obtained from one of these pollutants. 100 80 60 40 transmittance (%) 4000 3500 3000 2000 2500 wavenumber / cm1 1500 1000 500 What evidence is there in the spectrum that the pollutant may be a hydrocarbon rather than an alcohol or a carbonyl compound?[1]OCR 2011 Turn over<br />
 (e) The infrared spectrum of a drug is shown below. 20 transmittance (%) 100 80 60 40 20 4000 3500 3000 2000 2500 wavenumber / cm1 1500 1000 500 Suggest, with reasons, possible functional group(s) present in the drug.[2] [Total: 10]OCR 2011<br />

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