P, Q, R, S, T, U, and V are the seven structural isomers with molecular formula C5H10O that have a carbonyl group. P CH3(CH2)3CHO S (CH3)3CCHO V (CH3)2CHCOCH3 Q CH3CH2CH(CH3)CHO T CH3CH2CH2COCH3 R (CH3)2CHCH2CHO U CH3CH2COCH2CH3

1. (a)Only one of these seven compounds has stereoisomers. Draw three-dimensional diagrams of the two stereoisomers of this compound.[2]
2. (b)(i)P, Q, R, S, T, U, and V are treated separately with alkaline I2(aq) and the product mixture is acidified. Identify the two compounds that give a positive result with alkaline I2(aq). and[1]
3. (b)(ii)Describe the observations when one of the compounds you have identified in (b)(i) is treated with alkaline I2(aq) and give the structural formulae of the two carbon-containing products of this reaction. observations two carbon-containing products and[2]
4. (c)(i)The proton (1H) NMR spectra of P, Q, R, S, T, U, and V are compared. Identify the only compound that gives a spectrum with two singlets and no other peaks.[1]
5. (c)(ii)Fig. 7.1 shows the spectrum obtained from one of the compounds. [Figure 7.1] Identify the compound that gives this spectrum.[1]
6. (c)(iii)Name the splitting pattern of the peak at δ = 1.1 in Fig. 7.1. Give the reason for this splitting. name reason[1]
7. (c)(iv)Identify the substance that gives the small peak at δ = 0 in Fig. 7.1.[1]
8. (d)The carbon-13 NMR spectra of R, S, T and U are compared. Complete Table 7.1 to state the number of peaks in the spectrum of each compound. Table 7.1 compound number of peaks R (CH3)2CHCH2CHO S (CH3)3CCHO T CH3CH2CH2COCH3 U CH3CH2COCH2CH3[2]

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