This question was not popular. Responses from candidates showed that this section of the syllabus has not been adequately covered or treated. Part (a), most of the responding candidates could not describe what a functional group is but were able to state the functional group in the compounds listed. Part (b), most of the candidates could not give the correct products of the organic reactions and hence could not draw the structures of the products formed. Part (c) was poorly attempted. Most of the candidates could not write the correct equation for the preparation of butan-2-oƖ; from butene. Part (d), was also poorly attempted as most candidates could not give the correct reagents required for the conversion to take place. Part (e), most candidates could not state the correct observations. Instead of stating an effervescence for example, most candidates reported a colourless, odourless gas was evolved while few candidates were able to state that the bromine water was decolourised.
The expected answers are:
(a)(i) It is an atom or group of (bonded) atoms that is responsible for the Chemical
behaviour of an organic compound.
ii) I. – OH or hydroxyl group/alkanol
II. – C = O/carboxylic/alkanoic OH
(b)(i) I. H+, heat CH3COOH + CH3CH2 CH2 OH
II. NaOH, heat CH3(CH2)3CH2COONa + CH3 OH
(ii) I.
H H H H
O
H C C H C C C OH
H OH H H H
II. H H H H O H
H C C C C C ONa H C O H
H H H H H
(c) C4H8 + H -HSO4 C4H9HSO4
C4H9 HSO4 + H2O C4H9 HO + H2SO4
Accept
CH2 = CHCH2CH3 + H2O H+ CH3CHCH2CH3
OH
OR C4H8 + H2O H+ C4H9OH
(d) I. Conc. H2SO4/H3PO4
II. acidified KMnO4 /K2Cr207/Na2Cr2O7
III. ethanol Conc H2SO4
(e)(i) I. effervescence occurs
II. yellow precipitate
III. bromine water decolourised
(ii) O
I. - C - OH /alkanoic group
II. CH3CHOH/CH3 adjacent to CHOH
III. C = C / carbon – carbon double bond