Carbonyls, Carboxylic Acids & Esters HW (MS)
1.	(i)

a correct skeletal aldehyde is shown on C1 (1)
rest of the skeletal structure (C2-C10) correct (1)	2
 
(ii)	C9H15CH2OH + [O] → C9H15CHO (1) + H2O (1)	2
NOT COH,
allow C10H16O
[4]

 2.	CCl3CH(OH)2 + [O] → CCl3COOH + H2O (1)	1
[1]

 3.	(i)	aldehyde / C=O / carbonyl (1)	1
(ii)	C6H5CHCHCHO + 2[H] → C6H5CH=CHCH2OH (1)	1
allow C9H10O
[2]

 4.	(i)
 (1)	1
 
(ii)	C14H10O2 + 4[H] → C14H14O2 (1)	1
allow ecf from (i)
[2]

	

5.	(a)	(i)	heat with:
Tollens’ reagent / ammoniacal silver nitrate (1)
	to give: silver mirror / precipitate (1)	2 
(ii)	aldehydes can be oxidised to a carboxylic acid ora
/ aldehydes can reduce Ag+ to Ag (1)	1
(b)	(i)	CH3CH=CHCH2OH (1)
(either stereoisomer)	1
(ii)	reduction / redox / addition (1)
(NOT hydrogenation)	1
(c)	C4H6O + 5O2 → 4CO2 + 3H2O (1)	1
[6]

6.	(i)

1 mark for each curly arrow (1)(1)	2
(ii)
 (1)	1
(iii)	electron pair donor (1)	1
(iv)	electron pair on H– attracted to δ+ carbon forming a dative covalent bond (1)
the double/π electron pair breaks (1)
electron pair now on O– (1)	3
[7]

7.	(a)

	curly arrow from O of OH to C (1)
	dipole on C=O and curly arrow breaking C=O (1)
	structure of the intermediate (1)
	curly arrow from O (of the correct intermediate)
… to H of H2O (1) (allow O to H+ ion here)
	curly arrow breaking the H–O bond in H2O (1)	5
(b)	one mark for the correct answer to each step below with ecf throughout
steps may come in any order
	one week’s supply = 21× dose (1)	5.25 g / 0.0317mol
	mass of trichloroethanal =	4.68 g (223mg if done first)
0.891 × mass of chloral hydrate (1)
	60% yield = mass/moles x 100/60 (1)	7.8(0 g)	3
	common errors for two marks are:	9.82 g (mass ratio upside down)
	8.75 g (mass ratio not done)
2.60 g (3× not done), 1.11 g (7× not done), 0.371g (21× not done)
7798 g (mg to g not done) etc.
[8]

 8.	method
silver nitrate (1)
ammonia / ammoniacal (1)
warm / heat (1)
silver (mirror) / brown ppt forms (1)
	explanation
silver ions reduced / Ag+ + e– → Ag (1)
aldehyde oxidised to a carboxylic acid (1)
correct structure – eg C6H5CHCHCOO–/COOH (1)
	quality of written communication
mark for correct spelling, punctuation and grammar in at least two sentences (1)	8
[8]

 

9.	(i)
 (1)	1
(ii)	any sensible change in flavour linked to the
presence of the ester or loss of the acid (1) – e.g.
‘more fruity due to the ester’
‘less sour as acids get used up’	1
[2]

10.	(i)	flavouring / fruity smell etc	1
NOT perfume or sweetener
(ii)	conc H2SO4 (1)
reflux/ distil (1)	2
(iii)	CH3COOH + C9H15CH2OH → CH3COOCH2C9H15 + H2O	3
	(1)	(1)	(1)
allow C2H4O2 and C12H20O2
but NOT wrong structures
allow ecf on the wrong acid
[6]

11.	(1) for correct functional group (1) for the rest

C5H11 acceptable	2
[2]