[Figure 4.1] shows compounds J to M, each of which contains four carbon atoms. J: [Figure 4.1 shows CH3CH2CH2CHO] K: [Figure 4.1 shows CH3CH2COCH3] L: [Figure 4.1 shows CH3CH2CH(OH)CH3] M: [Figure 4.1 shows CH3CH2CH2COOH] [Figure 4.1]

1. (a)Table 4.1 gives details of tests on J to M. In each test, only two compounds give a positive result. Complete Table 4.1. Table 4.1 reagent | observation of positive result | compounds that give a positive result ---|---|--- acidified K2Cr2O7(aq) | | J and L alkaline I2(aq) | yellow precipitate | (blank) | orange precipitate | J and K Na(s) | | [5][5]
2. (b)K reacts with HCN in the presence of a KCN catalyst, forming N.
3. (b)(i)Complete [Figure 4.2] to show the mechanism for this reaction. Include charges, dipoles, lone pairs of electrons and curly arrows, as appropriate. [Figure 4.2][4]
4. (b)(ii)Identify the class of compound of which N is a member. [1][1]
5. (b)(iii)N has a chiral centre. Explain what is meant by a chiral centre. [1][1]

This question uses a diagram from the original paper, which isn't shown here. Open the full paper from the past papers archive to see it.