1.	(i)	120–130 (1)	1
(ii)	boiling point increases with increase in Mr/molecular formula/number of
carbon atoms/chain length (1)
more intermolecular forces/electrons/surface area/
surface interactions/van der Waal forces (1)	2
[3]

2.	(a)	C_6H_14	1
 
(b)	(i)	boiling point increases with increase in M_R/molecular formula/N° of
carbon atoms/chain length	1
(ii)	more intermolecular forces/electrons/surface area/
	surface interactions/van der Waal forces	1
(iii)	120 - 130 °C	1
[4]

3.	C_13H_28
[1]

4.	(i)	unsaturated contains a double/multiple/p bond 	1
hydrocarbon contains hydrogen and carbon only. 	1
(ii)	angle a 109 -110° 	1
angle b 117 -120° 	1
(iii)	

Diagram to show a minimum of 2 carbons, each with a s-bond
and p-orbitals 
Overlap of adjacent p-orbitals (in words or in diagram) 	2
[6]

5.	(i)	C_6H_10	1
(ii)	C_3H_5 / ecf to (i)	1
(iii)	M_r of cyclohexene = 82	1
% C = (72/82) ´ 100 = 88%	1
87.8% gets 1 mark
ecf to (i) and (ii) for both marks
Alternative calculation based on empirical formula:
Mass of empirical unit = 41, % C = (36/41) ´ 100 = 88%
[4]

6.	(i)	any two from methylcyclobutane, 1,1-dimethylcyclopropane and 1,2-dimethylcyclopropane

	allow

		2
(ii)	cyclopentane 	1
(iii)		1

[4]

7.	(a)	Same molecular formula, different structure /displayed formula/	2
arrangement of atoms/bonds 
	(Same formula, different structure/displayed formula/arrangement of atoms 
(b)	(i)	3-methylbut-1-ene and 2-methylbut-2-ene
(any unambiguous structure/formula is acceptable) 	2
(ii)	2-methylbut-1-ene/2-methyl-1-butene 	1
(iii)		1

[6]

8.	Bonding:	p-bond formed by overlap of (adjacent) p-orbitals/p-bond labelled on
diagram	1
diagram to show formation of the p-bond	1

Shape/bond angles:
tetrahedral around the CH_3	1
bond angle = 109°28/ (109-110°)	1
trigonal planar around each C in the C=C	1
bond angle = 120° (118-122°)	1
Cis-trans
cis & trans correctly labelled eg but-2-ene	1
require a double bond because it restricts rotation	1
	each C in the C=C double bond must be bonded to two different atoms
or groups	1
QWC		Allow mark for well constructed answer and use of three terms like:
	orbital, tetrahedral, trigonal, planar, rotation, spatial, stereoisomers,
geometric	1
[10]

9.	Structural/chain/positional isomers have the same molecular formula,
different structure	1
but-1-ene/ but-2-ene/ methylpropene	/ cyclobutane/ methylcyclopropane
(any three or two with correct structures and names)	3
4 marks for structural isomerism
Cis-trans /geometric isomerism	1
cis & trans but-2-ene clearly identified	1
C=C prevents rotation	1
each C in the C=C double bond must be bonded to two different atoms or groups	1
4 marks for cis-trans isomerism
QWC: Well organised answer making use of correct terminology to include
any three from: structural, geometric, cis-trans, molecular formula, restricted,
rotation, stereoisomerism, stereoisomers, chain isomerism, positional isomerism,
if all isomers are correctly named	1
[9]

Paddington Academy