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AQA Specimen Paper 3 Q5
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![0 5 13 A sample of ethanedioic acid was treated with an excess of an unknown alcohol in the presence of a strong acid catalyst. The products of the reaction were separated and analysed in a time of flight (TOF) mass spectrometer. Two peaks were observed at m/z = 104 and 118. . 1 Identify the species responsible for the two peaks. [2 marks] [4 marks] . 2 0 5 Outline how the TOF mass spectrometer is able to separate these two species to give two peaks. Barcode Typesetter code Turn over <br />](https://learnah.org/wp-content/uploads/2018/08/Specimen_QP_-_Paper_3_AQA_Chemistry_A-Level_5.jpg)
![MARK SCHEMEA-level ChemistrySpecimen paper 3 Marking guidance Mark AO Comments [CH3OCOCOOH]+ [CH3OCOCOOCH3]+ Positive ions are accelerated by an electric field To a constant kinetic energy The positive ions with m/z of 104 have the same kinetic energy as those with m/z of 118 and move faster Therefore, ions with m/z of 104 arrive at the detector first Allow names Do not allow molecular formula 1 1 1 1 1 1 AO3 1a AO3 1a AO1a AO1a AO2e AO2e 9 of 10 Question 05.1 05.2<br />](https://learnah.org/wp-content/uploads/2018/08/Specimen_MS_-_Paper_3_AQA_Chemistry_A-Level_5.jpg)