Carbonyls, Carboxylic Acids & Esters TEST (MS)

1.	(a)	(i)	silver mirror 
ALLOW Ag(s) OR Ag mirror OR precipitate OR ppt OR solid
ALLOW brown OR black OR grey
1
(ii)	HOCH2COOH 
ALLOW CH2OHCOOH OR CH2OHCO2H OR HOCH2CO2H OR displayed OR skeletal formula OR HOCH2COO–
DO NOT ALLOW C2H4O OR 2-hydroxyethanoic acid
1
(b)	HOCH2CHO + 3[O] →HOOCCOOH + H2O
	reagents		both products	
ALLOW displayed/skeletal formula/COOHCOOH 
if molecular formula used C2H4O2 + 3[O] → C2H2O4 + H2O
max = 1 
Any correctly balanced equation for partial oxidation can score 1 mark 
HOCH2CHO + [O] → HOCH2COOH
OR
HOCH2CHO + 2[O] → OHCCOOH + H2O
OR
HOCH2CHO + [O] → OHCCHO + H2O
OR
HOCH2CHO + 2[O] → HOOCCHO + H2O
2

(c)	(i)	HOCH2CH2OH 
ALLOW HO(CH2)2OH OR (CH2OH)2 OR skeletal formula OR displayed formula
DO NOT ALLOW molecular formula (C2H6O2)
1
(ii)	curly arrow from H– to Cδ+ 
dipoles and curly arrow from C=O bond to O 
ALLOW curly arrow to C even if dipole missing or incorrect
	intermediate 
	curly arrow from intermediate to H δ+ in H2O/ H+ and if H2O
is used it must show the curly arrow from the O–H bond to the O 
lone pairs are not essential
ALLOW maximum of 3 marks if incorrect starting material is used

Alternative 3 scores all 4 marks even though the intermediate is not shown
4
[9]

2.	(a)	(i)	Tollens’ reagent / ammoniacal silver nitrate (1)
	silver mirror / precipitate (1)
	butanoate / butanoic acid / unambiguous formula or structure (1)	3 
(ii)	Any of:
	Br2 – decolourises – (electrophilic) addition
Na – fizzes – redox
SOCl2 /PCl5 /acid chloride – white fumes –
	substitution/chlorination
carboxylic acid + conc H2SO4 /acid chloride – sweet smell –
	esterification/ condensation
	test (1) - observation (1) - type of reaction (1)	3
NOT
2-4DNPH to give no precipitate
(b)	recrystallise /purify (the precipitate) (1)
	measure melting point (1)
	compare with known values (1)	3
[9]

3.	(a)

propanoate and ester group (1)	2-methyl propyl (1)	2
(b)	propanoic acid (1)
(2-)methylpropan-1-ol (1)
	heat (1)
conc. H2SO4 (1)
(allow ecf from part (a) for the equation)
	CH3CH2COOH + CH3)2CHCH2OH → CH3CH2COOCH2CH(CH3)2 + H2O
	reactants (1)	products (1)	6
(c)	mass spectrum / spectrometry (1)
	molecular ion peak /
m/e or mass of the peak furthest right (1) AW	2
[10]

4.	(i)	H+ /acid / named strong acid eg H2SO4 / HCl	1
(ii)

displayed ester group (1)
rest of the ester (1)	2
[3]

5.	
 
ALLOW

DO NOT ALLOW incorrect bond linkage

[1]
 
6.	(a)	(i)	alkene (1)
ester (1)	2
allow “C=C double bond”
i.
 (1)	1
ii.	C12H14O2 (1)	1
(b)	same structural formula/order of bonds,
different spacial arrangement AW (1)
	description or diagram showing B and how it is different from A (1)	2

(c)

	(1)	(1)	2
(d)	(i)	peak at 1680-1750 (cm–1) due to C=O (1)
	peak at 1000-1300 (cm–1) due to C-O / (1)	2
(ii)	2500-3300 / 3230-3550 (cm–1) (1)
	O-H /carboxylic acid/alcohol is not present in A (1)
	allow 1 mark for ~500-1500 (cm–1) which is a unique
fingerprint region etc	2
[12]

 7.	(i)	hydrolysis (1)
	(sorbitan monolaurate is an) ester (1)
	broken down to form an alcohol and carboxylic acid/salt (1) AW
/ equation to show the reaction	3
(ii)	sorbitan monolaurate is made from a renewable resource
/ not based on crude oil (1) AW	1
[4]
 
8.	Three of following points: (1)(1)(1)
•	1. There is van der Waals (IDID) between triglycerides.
•	2. There is van der Waals between triglycerides and (non-polar) solvent.
•	3.Triglycerides cannot hydrogen bond (to water)(enough).
•	Because there are not enough suitable sites/oxygen atoms
Or long hydrocarbon chains do not hydrogen
bond/would interfere with hydrogen bonding in water
AW	3
[3]

9.	(i)	

Accept correct skeletal form (even if only for acyl groups)
but must have 17C and two double bonds/one triple bond	2
(ii)	6. Ecf from (i). (1)	1
[3]
 
10.	(i)	CH3COOH (1)	1
(iv)	CH3COOH (1)
CH3CH2OH (1)	2
 [3]