2.10 ALCOHOLS EXTRA QUESTIONS MS
1.	(a)	C4H8O          ®        C5H9NO
Mr = 72  (1)               Mr   = 99  (1)
If MF shown lose 1 for wrong Mr.
If no MF shown max 2 if Mr wrong
5g	®          × 99  (1)     (= 6.88g)
64% yield  =  0.64 ×  × 99  =  4.40g  (1)
(allow answer 4.36 – 4.42)	4
(b)		butanone has peak at ~ 1700 cm–1  (1)
(but not at ~ 3350 cm–1)
B  has peak at ~ 3350 cm–1  (1)
(but not at ~ 1700 cm–1)	4
 
(c)		1
[9]

2.		Catalyst (c) phosphoric acid or (c) sulphuric acid (1)  
Not dilute
accept correct formula
Conditions	Temp = High or 200–500°C (1)
Temp = medium or moderate or 50-100°C
Pressure = High or 5–20 Mpa or 50–200 atoms
Pressure = High or 2–4 Mpa or 20–40 atoms
If. wrong, no catalyst given, allow phosphoric acid conditions
 
Equation	CH2 = CH2 + H2O ® CH3 CH2 OH
				
		allow C2H4	 allow C2 H5OH
	not CH2 CH2	4
 
 [4]

3.	(a)	C4H10O + 6O2 ® 4CO2 + 5H2O  (1)	1
 
(b)	(i)     two H on carbon in double bond  (1)
(ii)	
Z but-2-ene  (1) E but-2-ene	3
[4]

4.	(a)	(i)	3-methylpentan-3-ol (1)
(ii)	carbonium ion/carbocation (1)
 
(iii)	
		5 
(b)	lone pair (1)
(c)	(i)	orange (1)
	tertiary alcohol (1)
not oxidised (1)
(ii)	two from:
(2x1)	5
[11]

5.	(a)	A = tertiary alcohol/ 3° (1)
B = secondary alcohol/ 2° (1)	2
(b)	(2)-methylpropan-2-ol (1)	1
 
(c)	(i)	(selects isomer C and) gives suitable structure for butanal (1)
or
(selects isomer D and) gives suitable structure for
2-methylpropanal  (1)	1
(ii)	(sodium / potassium) dichromate / manganate VII  (1)
	acidic conditions / H+ (this mark dependent on first mark) (1)
not HCl with KMnO4
distill(ation)      not reflux  (1)	3
 
(d)	(i)	removal of water (1)	1
(ii)	alkene / ether (not a named example) (1)	1
(iii)	concentrated sulphuric acid / concentrated or solid phosphoric acid
(strong) heat / high temperature / 150 – 200 °C / reflux
or
suitable catalyst eg aluminium oxide / broken porcelain  (1)
strong heat / high temperature / 300+ °C  (1)
mark for conditions dependent on mark for reagents	2
(iv)	(selects isomer C and) gives suitable structure for but-1-ene
(accept but-2-ene structure if primary to secondary carbocation
rearrangement mentioned)
or
(selects isomer A or D and) gives suitable structure for
2-methylpropene (1)
also accept structures for ethers	1 
(v)	selects isomer B  (1)
suitable structure for but-1-ene (mark independently of isomer
chosen) (1)
suitable structure for but-2-ene (either cis or trans not both) (1)
	dehydration ‘involves the removal of OH and H to make water,
and H can be
either from C1 or from C3 so two isomers formed  (1)	4
[16]
6.	(a)	(i)	Equation

Colour change	orange ® green
(ii)	Reagent	ammoniacal silver nitrate/Tollens (1)
Observation with oxidation product of butan-1-ol	silver mirror (1)
Observation with oxidation product of butan-2-ol	no reaction (1)	6
 
(b)	Butanoic acid (1)	1
(c)	Structure of isomer 1	Structure of isomer 2
   (1)	(1)
Name of isomer 1	2-methylpropan-1-ol (1)
Name of isomer 2	2-methylpropan-2-ol (1)	4
[11]

7.	(a)	(i)	Electron pair/ lone pair acceptor OR seeking/bonds
with an electron pair	1
(insist on reference to a pair of electrons)
 
(ii)	M1 curly arrow from middle of C=C bond of the alkene towards/
alongside the H atom of the H-Br;	1
(penalise arrows which go towards one of the carbon atoms) (ignore a partial negative charge on the C=C)
	M2 curly arrow from H-Br bond to side of Br atom;	1
(penalise M2 if there are formal charges on HBr or if there are partial charges which are the wrong)
(penalise M2 if the single bond has two dots in addition to the line)
	M3 correct structure for carbocation;	1
(penalise M3 if the positive charge is placed on the end of a bond) (penalise M3 if any alkene other than ethene is used - all other marks can score)
	M4 curly arrow from lone pair on bromide ion to the positive carbon 	1
of carbocation, ensuring that bromide ion has a negative charge;

(b)	(i)	M1: potassium cyanide OR KCN OR sodium Cyanide OR NaCN;	1
(ignore conditions - dissolved in (aq) or (alc) or KOH(aq) all work) (penalise HCN)
M2: propanenitrile;	1
(credit propan-1-nitrile OR propan nitrile, but not propanitrile)
 
(ii)	M1: ammonia OR NH3;	1
(If formula is written, insist that it is correct)
(ignore conditions, but penalise acidic)
M2: ethylamine;	1
(credit aminoethane)

(iii)	M1: curly arrow from lone pair on nitrogen of (correct formula for)
ammonia towards/alongside C atom of C-Br;	1
(penalise M1 if formula of ammonia is wrong or has a negative charge or has no lone pair or arrow is from negative charge)
	M2: curly arrow from C-Br bond towards/alongside side Br atom;	1
(credit M2 independently)
(penalise M2 if formal positive charge on C atom of C-Br)
	M3: correct structure of the ethylammonium ion;	1
(credit the structure drawn out with all four bonds around the nitrogen atom OR written as C2H5NH3+ OR CH3CH2NH3+)
 
	M4: curly arrow from the middle of one of the H-N bonds towards the
positive N atom;	1
(possible to credit M4 on an incorrect ethylammonium ion with no positive charge)
(ignore use of ammonia or bromide ion etc. to remove proton from ethylammonium ion)
(If the wrong haloalkane is used, award MAX. 3 marks for the mechanism) (If SN 1 mechanism is used, give full credit in which M1 is for a curly arrow from the lone pair of the N atom of (correct formula for) ammonia towards/alongside the positive carbon atom of CH3CH2+)
[17]

8.	 (a)	Reagents	H2SO4 or H3PO4 or Al2O3 (1)
Name of mechanism	elimination (1)
Mechanism

 (b)	Type of isomerism 	geometrical or cis-trans (1)
	Explanation 	restricted rotation or
	double bond rigid (1)	2
[4]

9.	(a)	electrophilic addition	1
M1: curly arrow from C=C bond towards/alongside the side of H atom on
H1OSO2OH	1
(penalise M1 if arrow to H2SO4 OR to formal charge on H of H1O bond)
(ignore partial charges on H and O of H2SO4, but penalise if these are
incorrect on the H atom being attacked)
(credit M1 and M2 if correct curly arrow to H+ provided the anion is present)
M2: curly arrow from H–O bond towards/alongside the side of the O atom on
H–OSO2OH	1
(credit the arrow even if there are partial or formal charges on H and O
but the structure of H2SO4 is correct)
M3: correct structure of the carbocation	1
(penalise use of ‘sticks’ in this structure)
M4: curly arrow from lone pair on an individual oxygen atom of
(correct formula for) hydrogensulphate ion towards/alongside C atom
bearing the positive charge	1
(insist that the an ion has the correct formula with a lone pair of
electrons and a negative charge)

(b)	(i)	ethanal	1
correct structure for ethanal	1
(aldehyde functional group must be drawn out)
 
(ii)	oxidation or redox	1
[8]

10.	(a)	(i)	C6H12O6 ® 2C2H5OH + 2CO2	1
(Or CH3CH2OH)
(Ignore state symbols in the equation)
(ii)	Fermentation	1
 
(b)	(i)	C2H5OH + 3O2 ® 2CO2 + 3H2O	1
(Or C2H6O or CH3CH2OH)
(ii)	CO or carbon monoxide or C or carbon ONLY	1
(iii)	2CO + 2NO ® 2CO2 + N2
OR 2NO ® N2 + O2
OR 2NO + C ® N2 + CO2
OR C8H18 + 25NO ® 8CO2 12½N2 + 9H2O	1
(In equation 2, allow additional O2 on both sides of the equation) 
(c)	Elimination	1
(Penalise additional words such as “electrophilic”)	
[6]

11.		Step 3
dehydration or elimination  (1)
H2SO4 or H3PO4 or A12O3  (1)	2
 
[2]
12.	(a)	% O = 21.6 % (1)
If % O not calculated only M2 available
C 	H 	O  (1)	
= 5.41	= 13.5	= 1.35	
Ratio: 4 : 10: 1 	(\ C4H10O) (1)
If arithmetic error in any result lose M3
If percentage composition calculation done zero
		3
(b)	(i)	Type of alcohol: Tertiary (1)
Reason: No hydrogen atom on central carbon (1)
(ii)	
Penalise missing bonds / incorrect bonds once per paper
		4
(c)	(i)	Aldehyde (1)
Ignore named aldehydes or their structures,
penalise wrong named compound
(ii)	CH3CH2CH2CH2OH + [O] ® CH3CH2CH2CHO + H2O (1)
Balanced (1)
C4H10O is OK as a reactant
[O] can be over arrow
C3H7CHO not accepted for product, but C2H5CH2CHO is OK
If use C3 or C5 compounds no marks in (ii) C.E of wrong alcohol
(iii)	Name Butanoic acid (1)
Structure: CH3CH2CH2COOH (1)	5
(d)	Advantage: Fast reaction OR pure product OR continuous process
OR cheap OR high yield,100% alcohol (1) 
Disadvantage: High technology OR ethene from non renewable source
OR expensive equipment not just costly (1)
Not answers based on fermentation
		2
[14]
13.	 	(i)	3-methylbutan-2-ol (1)
No alternatives 
(ii)	elimination or dehydration (1)
 
(iii)	(c) H2SO4 or (c) H3PO4 – name or correct formula (1)
 
(iv)	
Double bond must be shown
Accept any correct unambiguous structures
if but- 1-ene and but-2-ene offered, allow M2
		5
[5]
14.		(i)	C6H12O6 ® 2C2H5OH + 2CO2;	1
(penalise C2H6O once only in this question)
(ii)	Concentrated H2SO4 OR concentrated H3PO4 OR A12O3;	1
(penalise aqueous or dilute as a contradiction)
C2H5OH ® C2H4 + H2O OR C2H5OH ® H2C = CH2 + H2O;	1
(penalise CH2.CH2 and CH2-CH2 and CH2:CH2 for ethene)
 
 [3]

15.	(a)	(i)	correct graphical formula for tertiary alcohol
allow CH3 not C2H5 (1)
	2-methylbutan-2-ol / 2-hydroxy-2-methylbutane / 2-methyl-
2-hydroxybutane award name mark even if it follows 
incorrect formula (1)	2
(ii)	graphical formula of pent-1-ene (1)
	graphical formula of pent-2-ene (1)	2
	accept geometrical isomers of pent-2-ene if clearly shown to be different
 
(iii)	dehydration / elimination (1)	1
(iv)	no H atoms on C atom next to C–OH / three methyl groups on C (1)	1
 
 [4]
16.	(a)	(i)	nucleophilic substitution (1)
(ii)	tertiary alcohol or no H atom available (1)	2

(b)	Name of mechanism 	elimination (1)
Mechanism 

		4
 
(c)	Structure 

Name 	2-ethylbut-1-ene (1)	2
[8]
 
17.		(i)	substitution or hydrolysis (1)
nucleophile (1)
 
(ii)	

 
(iii)	tertiary or no C–H (1)	6
 
 [6]

18.	(a)	M1	fermentation	1
M2	dehydration or elimination	1

(b)	(i)	yeast OR zymase OR an enzyme	1
(ii)	concentrated sulphuric or phosphoric acid	1
(penalise aqueous or dilute as a contradiction)
 
(c)	(i)	primary or 1°	1
(ii)	sugar or glucose or ethanol is renewable	1
OR ethanol does not contain sulphur-containing impurities
OR ethanol produces less pollution or is less smoky or less CO/C
(the objective is a positive statement about ethanol)
(penalise the idea that ethanol is an infinite source or vague statements that ethanol has less impurities) (penalise the idea that ethanol produces no pollution)
 
(d)	C2H6 ® C2H4 + H2	1
 
(e)	Addition	1
(ignore self or chain as a preface to “addition “)
(penalise additional)
[8]

19.	(a)	(i)	CH3 CH2 CH2 CH2 CH2 OH + [O] ® CH3 CH2 CH2 CH2 CHO + H2O (1)
(equation balances (1))
	
allow C4 H9 CH2 OH	product must show aldehyde group
	or C5 H11 OH	e.g. C4 H9 CHO 
If ketone shown here, allow balance
If wrong alcohol used, allow balance
(ii)	CH3 CH2 CH2 CH(OH)CH3 + [O] ® CH3 CH2 CH2 COCH3 + H2O (1)
(equation balances (1))
	
allow C3 H7 C(OH) CH3	product must show CO in ketone
	or C5 H11 OH	e.g. C3 H7 COCH3 
If aldehyde show here, allow balance
If wrong alcohol used, allow balance	4
(b)	Fehling’s solution or Tollen’s reagent or Potassium dichromate (1)
¬¾ Boil, heat, warm ¾® ammoniacal silver nitrate
Conditions tied to reagent
orange or brown or red precipitate or solid etc  
or	silver mirror grey/black precipitate of solid
or	(orange) turns green or blue
observation tied to reagent
		4
 
No precipitate
or	no silver mirror
or	no colour change (1)
or	no reaction ¾®
Not “nothing”
If no reagent or wrong reagent quoted, mark as ‘CE’
Any appropriate reagent - e.g. - Benedicts, but if Cr2O72– or [Ag CNH3)2]+
or MnO4– given, do not allow reagent mark.
[8]

20.	(a)	M1:	CH3CH2CH2CH2OH;	1
M2:	CH3CH(OH)CH2CH3;	1
(penalise incorrect alcohols in part (a), but mark consequentially in part (b) and in part (c), if relevant)
(if three alcohols drawn, award MAX. 1 mark)
 
(b)	M1, M2 and M3:	Correct structures for butanal, butanone and butanoic acid;	3
(award these structure marks wherever the structures appear, but insist that the C=O is shown in each structure and additionally, the C-O in the carboxylic acid
M4:	balanced equation for the reaction of butan-1-ol with [O] to
produce butanal and water;	1
M5:	balanced equation for the reaction of butan-1-ol with [O] to
produce butanoic acid and water
OR
	balanced equation for the reaction of butanal with [O] to
produce butanoic acid;	1
	M6: balanced equation for the reaction of butan-2-ol with [O] to
produce butanone and water;	1
(Credit condensed structures or molecular formulas in each equation, provided it is obvious to which reaction the equation refers) (Insist that whatever formula is used in each equation that it is a conventional representation of the compound; for example penalise CH3CH2CH2COH for butanal)
 
(c)	M1:	Correct structure for 2-methylpropan-2-ol;	1
M2:	2-methylpropan-2-ol
OR
methylpropan-2-ol;	1
(penalise on every occasion in parts (a) and (c), structures for the alcohols that are presented with the alcohol functional group as C-H-O)
[10]

21.	(a)	K2Cr2O7/H2SO4 reduced by
	CH3CH2CH2CH2OH (1)
	oxidised to	CH3(CH2)2CHO (1)
and	CH3(CH2)2COOH (1)
CH3CH2CH2CHO (1)
	oxidised to	CH3(CH2)2COOH (1)
Equation:	Cr2O72– + 14H+ + 6e– ® 2Cr3+ + 7H2O (1)	6
Note: Deduct one if all three compounds given as reducing agents.
 
(b)	Tollens’ reduced by
	CH3CH2CH2CHO (1)
	oxidised to	CH3(CH2)2COOH (1)
Equation	[Ag(NH3)2]+ + e– ® Ag + 2NH3 (1)	3
 [9]

22.	(a)	Reaction 1	H2O or steam (1)
Reaction 5	NH3 (1)	2
For Reaction 4; credit dil H2SO4 OR H2SO4(aq) OR HCl (aq) but NOT steam and NOT NaOH(aq)
 
(b)		4

Penalise M2 incorrect d+ / d–
Penalise d– on alkene (M1)
Penalise dots on bonds once
Penalise M4 (structure) for use of wrong alkene
Penalise M1 for use of Br2 
(c)	Water OR aqueous solution OR (aq) in equation (1)	M1
	Yeast OR enzyme/zymase OR T £ 45°C	M2
but T not below 20°C and allow warm
N.B. yeast and T=60°  con
Ignore pH
Ignore anaerobic / oxygen
Ignore time
Ignore pressure
	C6H12O6 ® 2C2H5OH (or CH3CH2OH) + 2CO2	M3
Allow C12H22O11 if balanced equation
M4 OR M5 needs the use of good English and correct chemistry to gain credit
M4:		The rate of fermentation is slower (1)
OR	The rate of hydration is faster
QoL	OR	(The rate of) fermentation is slow and
	(the rate of) hydration is fast
reference correctly to time rather than rate gains credit
M5:		The product of fermentation is less pure or lower purity
OR	The product of hydration is more pure or higher purity
OR	The product of fermentation is impure and that of hydration is pure
OR	Specific reference to 10–15% versus 90–100%
OR	correct reference to higher or lower yield	5
[11]

23.	
	
NaOH (1)          aqu or warm (1) 
nucleophilic substitution (1)

K2Cr2O7          H2SO4
Reflux (1)	
 
	CH3CH2OH + 2[O] ® CH3COOH + H2O (1)
[9]

24.	(a)	CH4 + Cl2 ® CH3Cl + HCl (1)
Initiation: Cl2 ® 2Cl. (1)
Propagation: CH4 + Cl. ® CH3. + HCl (1)
	 CH3. + Cl2 ® CH3Cl + Cl. (1)
Termination: CH3. + Cl. ® CH3Cl (1)
	or CH3. + CH3. ® C2H6	5

(b)	Hydration: H3PO4 (1)
	300°C (1)
	65 atmos (1)
Fermentation:	yeast (1)
	35°C (1)
	air free (1)
Advantages:	Two from
	faster/purer product/continuous process
(cheaper on manpower) (2)
Disadvantage:	ethene is non-renewable resource (1)	9
[14]

25.	(a)	Reaction 2: NaOH OR KOH (1) M1	alcohol (ic) OR ethanol (ic)(1) M2
ignore heat
Condition mark linked to correct reagent but award M2 if OH– or base or alkali mentioned
Reaction 3: concentrated H2SO4 OR H3PO4 M1 (1)	heat (1) M2
		OR 150°C - 200°C	4
Condition mark linked to correct reagent but award M2 if H2SO4 or H3PO4, but not concentrated
Penalise reagent and condition if dilute H2SO4 / H3PO4
 (b)	Mechanism:

Award M3  independently 
M1 and M2 must be to / from correct places
E1 mechanism possible in which M2 
Name: of mechanism = elimination (1)
NOT dehydrohalogenation
Ignore “base” OR “nucleophilic” before elimination
Reason: Reaction 2 has (very) low yield (1)	5
QoL	OR chloroethane has to be made (from ethane)
	OR chloroethane is expensive
	OR chloroethane is not redily available
(c)	Name of mechanism = elimination (1)
NOT dehydration alone
Reason: Ethanol could come from (fermentation of) renewable	2
QoL	sugars / glucose / carbohydrates / sources (1)
[11]

26.	(a)	A – alkene  (1)
B – halogenoalkane / bromoalkane / alkyl halide / haloalkane  (1)
C – alcohol (ignore primary, secondary)  (1)	3
 
(b)	(i)	addition ignore nucleophilic / electrophilic / free radical  (1)	1
(ii)	substitution not replacement / displacement  (1)	1
(iii)	oxidation not reduction; not redox; allow dehydrogenation  (1)	1
(c)	Sodium hydroxide / NaOH / KOH not just hydroxide (1)
	(B to C)	aqueous not dilute  (1)
(B to A)	alcoholic (1)
	mark alternatives as (d)
ignore references to concentration and temperature	3
 
(d)	sodium (or potassium) dichromate / Na2Cr2O7 or  (1)
named alkali or water or aqueous
	sulphuric acid / H2SO4
ignore dilute / concentrated (1)
allow HCl, H3PO4, HNO3
 
	allow KMnO4 with H2SO4 / H3PO4 / HNO3 not HCl
allow 1 mark for acidified dichromate or dichromate / H+
	heat / reflux / boil / warm / temperature 40°C ® 100°C  (1)
this mark dependent on ‘dichromate’ or ‘manganate’	3
 
(e)	(i)	CH3CH(CH3)Br + NaOH ® CH3CH=CH2 + NaBr + H2O  (1)
(ii)	CH3CH(CH3)Br + NaOH ® CH3CH(CH3)OH + NaBr  (1)
	allow molecular formulae C3H7Br; C3H8O; C3H6
allow ionic versions (with OH–, Br–)	2
 (f)	arrow from O of OH– to C joined to Br  (1)
lone pair not needed
	C–Br polarity shown by d+ d– or
heterolytic fission of C–Br bond shown by arrow from bond between C
and Br to Br or
intermediate with partial bonds and minus sign  (1)
Br– as product  (1)
allow all 3 marks if 1-bromopropane identified as B	3
 [17]