CIE Jun 2017 v1 Paper 2 Q4

Answers available below

P, Q and R all have the molecular formula C3H6O. They are all structural isomers of each other. PMT P and Q each contain an oxygen atom bonded directly to a carbon atom that is sp2 hybridised. R contains an oxygen atom bonded directly to a carbon atom that is sp3 hybridised. (a) (i) Explain the meaning of the term structural isomers.[2] (ii) Explain how sp2 and sp3 hybridisation can occur in carbon atoms. sp2 hybridisationsp3 hybridisation[2] (iii) State the bond angles normally associated with each type of hybridisation in carbon atoms. sp2sp3[2] (b) R contains two different functional groups, one of which is an alkene group. R reacts with cold, dilute, acidified manganate(VII) ions to form propane-1,2,3-triol. HO C OH OH propane-1,2,3-triol (i) Give the displayed formula of R.UCLES 2017 9701/21/M/J/17 [1]<br /> PMT (ii) State the type of reaction and what you would observe when R reacts with bromine water.[2] (iii) Draw the structure of the product formed when R reacts with bromine water. (iv) Identify acidified manganate(VII) ions. the gaseous product formed when R reacts with hot, concentrated,[1] [1] (c) P and Q (C3H6O) both form an orange precipitate when reacted with 2,4-DNPH. Only Q produces a yellow precipitate when reacted with alkaline aqueous iodine. (i) Name P and Q. PQ[2] (ii) Identify the yellow precipitate formed by the reaction of Q with alkaline aqueous iodine.[1] (d) P and Q each react with hydrogen cyanide to form a single product. The product formed from P exists as a pair of optical isomers. The product formed from Q does not exhibit optical isomerism. (i) Explain the meaning of the term optical isomers.[2]UCLES 2017 9701/21/M/J/17 [Turn over<br /> 10 (ii) Ethanal, CH3CHO, also reacts with hydrogen cyanide. The product of this reaction is CH3CH(OH)CN. Draw the mechanism of this reaction. Include all necessary charges, dipoles, lone pairs and curly arrows. PMT [3] [Total: 19]UCLES 2017 9701/21/M/J/17<br />

Show answer