Page 2. (1)-methylethyl ethanoate OR. Propan-2-yl ethanoate Ignore extra or missing spaces, commas or hyphens 1. (ii) M4 for 3 arrows and lp

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1 M.(a) (i) (CH 3 ) 2 CHOH + (CH 3 CO) 2 O CH 3 COOCH(CH 3 ) 2 + CH 3 COOH Allow CH 3 CO 2 CH(CH 3 ) 2 and CH 3 CO 2 H Ignore (CH 3 ) 2 C in equation ()-methylethyl ethanoate OR Propan-2-yl ethanoate Ignore extra or missing spaces, commas or hyphens (ii) M4 for 3 arrows and lp NO Mark for name of mechanism M for lone pair on O and arrow to C or to mid-point of space between O and C M2 for arrow from C=O bond to O M2 not allowed independent of M, but allow M for correct attack on C+ + rather than δ+ on C=O loses M2 If Cl lost with C=O breaking, max for M M3 for correct structure with charges (penalise wrong alcohol here) but lone pair on O is part of M4 Penalise (CH 3 ) 2 C in M3 M4 for lone pair on O and three arrows Only allow M4 after correct / very close M3 M4 can be gained over more than one structure Ignore Cl removing H + 4 Page 2

2 (b) (i) Penalise covalent Na e.g. -O-Na LHS RHS (ii) C 7 H 33 COOCH 3 Allow C 9 H 36 O 2 [9] M2.(a) (i) (nucleophilic) addition-elimination Not electrophilic addition-elimination Ignore esterification M3 for structure If wrong nucleophile used or O H broken in first step, can only score M2. M2 not allowed independent of M, but allow M for correct attack on C+ + rather than δ+ on C=O loses M2. If Cl lost with C=O breaking lose M2. M3 for correct structure with charges but lone pair on O is part of M4. Only allow M4 after correct / very close M3. Ignore HCl shown as a product. 4 Page 3

3 a (ppm) or single value or range entirely within this range If values not specified as a or b then assume first is a. b (ppm) or single value or range entirely within this range (ii) Must have trailing bonds, but ignore n. OR OCH 2CH 2CH 2CH 2CO OR CH 2CH 2CH 2CH 2COO Allow but not - C 4H 8 one unit only Condensation (b) Tollens Fehling s / Be nedicts Acidified potassium dichromate Penalise wrong formula for Tollens or missing acid with potassium dichromate but mark on. J No reaction / no (visible) change / no silver mirror No reaction / no (visible) change / stays blue / no red ppt No reaction / no (visible) change / stays orange / does not turn green Ignore clear, nothing. Page 4

4 Penalise wrong starting colour for dichromate. K Silver mirror / grey ppt Red ppt (allow brick red or red-orange) (orange) turns green J Two (peaks) Allow trough, peak, spike. K Four (peaks) Ignore details of splitting. If values not specified as J or K then assume first is J. (c) If all the structures are unlabelled, assume that the first drawn ester is L, the second ester is M; the first drawn acid is N, the second P. The cyclic compound should be obvious. L ester OR H 2C=C(CH 3)COOCH 3 All C 5H 8O 2 L to P must have C=C. Allow CH 3. Allow -CO 2CH 3 etc. Allow CH 2C(CH 3)COOCH 3. M ester Page 5

5 CH 3CH=CHCOOCH 3 CH 3CH=CHOOCCH 3 CH 3CH=C(CH 3)OOCH CH 3CH=CHCH 2OOCH CH 3CH 2CH=CHOOCH Allow either E Z isomer. Allow CH 3 or C 2H 5 but not CH 2CH 3. Allow CH 3CHCHCOOCH 3 etc. N acid H 3 (CH 3) 2C=CHCOOH H 2C=C(CH 3)CH 2COOH H 2C=C(COOH)CH 2C Allow CH 3 or C 2H 5 but not CH 2CH 3. Allow CO 2H. Not cyclic isomers. Not the optically active isomer. Allow (CH 3) 2CCHCOOH etc. P acid Allow CO 2H. CH 3CH(COOH)CH=CH 2 Allow CH 3CH(CO 2H)CHCH 2 or CH 3CH(CO 2H)C 2H 3. Page 6

6 Q Not cyclic esters. [9] M3.(a) CH 3(CH 2) 4COOH Allow molecular formulae. CH 2OHCHOHCH 2OH Allow one mark only if formulae are swapped in position. (b) Keeping the foodstuff dry Allow an answer which refers to removal of water from the environment. Do not allow dehydration / removal of water from the fat. (c) They (antioxidants) react with free radicals And they are used up in the reaction / do not remain behind after reaction Lose one mark for any reference to catalysts can t slow down a reaction. (d) Mol of fat = (2.78 / 806 =) Page 7

7 Mol of NaOH = = mol of fatty acid Mol of NaOH = Mol of fat hydrolysed = Mol of fat hydrolysed = ( / 3 =) Mass of fat hydrolysed = g Percentage hydrolysed = Percentage hydrolysed = Do not penalise precision at any point. Since there are a variety of approaches to this calculation, award four marks for a correct answer but it must be clear that there is some relevant working. The answer alone gets M4 only. Any incorrect use of the 3: ratio is CE lose M3 and M4. [9] M4.(a) Mg + 2C 6H 4(OH)COOH (C 6H 4(OH)COO) 2Mg + H 2 Accept multiples, including fractions. (b) Gas syringe / inverted burette over water / measuring cylinder over water Collection apparatus must show graduations or be clearly labelled (eg syringe, burette, measuring cylinder). [2] M5.(a) (i) 3CH 3OH Not molecular formula Page 8

8 HOCH 2CH(OH)CH 2OH (ii) 9CO 2 + 9H 2O Or doubled C 7H 35COOCH ½ or 55/2 O 2 Consequential on correct right-hand side (b) (i) A0.7 Ethanol6.4 Water3.6 (ii) No effect If wrong, CE= 0 Equal moles on each side of equation OR V cancels Ignore moles of gas (iii) M Must have all brackets but allow ( ) Page 9

9 (iv) M2 If K c wrong can only score M4 for units consequential to their K c working in (b)(iv) M (min 2dp) M4 No units [3] Page 0