5 (a) But-2-ene reacts with KMnO₄ to form organic product, Y. Y does not react with Na2CO3. A gas is produced when an excess of Na is added to Y. (i) Describe the conditions for the KMnO₄ used in the reaction to form Y from but-2-ene. (ii) 24.0 cm³ of gas is produced when an excess of Na is added to 0.001 mol of Y, when measured under room conditions. Assume that 1 mol of gas occupies 24.0 dm³ under room conditions. Deduce a possible structure of Y. Explain your answer. (b) Z contains three types of atom: carbon, hydrogen and a halogen. The mass spectrum of Z is recorded. Fig. 5.1 shows a section of the mass spectrum at m/e greater than 63. The fragment at m/e = 64 is the molecular ion peak. [Figure 5.1] (i) Deduce the number of carbon atoms present in a molecule of Z using Fig. 5.1. Show your working. (ii) Deduce which halogen is present in Z using Fig. 5.1. Explain your answer. (iii) There are also peaks at m/e = 29 and m/e = 49. Suggest the formulae of these fragments. Deduce the name of Z. m/e = 29 m/e = 49 name of Z

1. (a)(i)Describe the conditions for the KMnO₄ used in the reaction to form Y from but-2-ene.[1]
2. (a)(ii)24.0 cm³ of gas is produced when an excess of Na is added to 0.001 mol of Y, when measured under room conditions. Assume that 1 mol of gas occupies 24.0 dm³ under room conditions. Deduce a possible structure of Y. Explain your answer.[3]
3. (b)(i)Deduce the number of carbon atoms present in a molecule of Z using Fig. 5.1. Show your working.[1]
4. (b)(ii)Deduce which halogen is present in Z using Fig. 5.1. Explain your answer.[1]
5. (b)(iii)There are also peaks at m/e = 29 and m/e = 49. Suggest the formulae of these fragments. Deduce the name of Z. m/e = 29 m/e = 49 name of Z[3]

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