Z is a molecule which contains the elements carbon, hydrogen and oxygen only. Z contains only alkene and carboxyl functional groups.

1. (a)Complete Table 6.1 by describing the observations that occur when two different reagents are added to separate samples of Z(aq). Table 6.1 reagent added to Z(aq) observation Br₂(aq) Na₂CO₃(s)[2]
2. (b)Table 6.2 shows the percentage by mass of each element present in Z. Table 6.2 element percentage by mass/% carbon 41.38 hydrogen 3.45 oxygen 55.17 Using the data in Table 6.2, demonstrate that the empirical formula of Z is CHO. Show your working.[1]
3. (c)(i)Fig. 6.1 shows the mass spectrum of Z. Deduce the molecular formula of Z. Explain your answer by referring to the molecular ion peak in Fig. 6.1 and the empirical formula of Z.[1]
4. (c)(ii)Use Fig. 6.1 to suggest the formulae of the fragments with m/e peaks at 45 and at 71. m/e 45 ............................................................................................................................................ m/e 71 ............................................................................................................................................[2]
5. (c)(iii)Suggest the structure of Z using relevant information from Table 6.1, (b) and (c).[1]

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