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BASIC CONCEPTS, ALKANES AND ALKENES TEST MS

1.	(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]

2.	(i)	Cl_2 ® 2Cl·	1
(ii)	uv (light)/high temperature/min of 400  C/sunlight	1
(iii)	Cl· + C_6H_12	® C_6H_11· + HCl
C_6H_11· + Cl_2	® C_6H_11Cl + Cl·	2
(iv)	react with each other/suitable equation
		1
 [5]

3.	(a)	(i)	C_5H_8	1
(ii)	C_5H_8	1
 
(b)	(i)	Ni/Pt/Pd	1
(ii)	1 mark for C_5H_12	1
1 mark for correct balancing	1
(iii)	

		1
[6]

4.	(i)	electrophile: lone pair (of electrons) acceptor. 	1
(ii)	

	essential mark intermediate carbocation/carbonium ion, accept primary
/”triangular”/ 
essential mark product 
curly arrow from double bond to Br_2 
curly arrow showing movement of electrons in the Br-Br bond or the dipole in
the Br-Br 
curly arrow from lone pair of electrons in Br^- to intermediate 
mark any errors first
		5 max
[5]

5.	structural isomerism:
structural isomers: same molecular formula, different structural formula (1)
structural isomers of but-1-ene: but-2-ene (1) and methylpropene (1)
	geometric isomerism
C=C prevents rotation of the double bond (1)
each C in the C=C double bond bonded to 2 different atoms or groups (1)
	 a clear statement that links non-rotation of the double bond to the
idea of groups being trapped on one side of the double bond (1)
	cis but-2-ene clearly identified (1)
trans but-2-ene clearly identified (1)
[7]

6.	Recognises that either a catalyst or high temperature (heat is not	1
sufficient) is required
cracking	suitable balanced equation	1
reforming	equation or statement indicating formation of a ring/cyclic
compound
suitable balanced equation with H_2		1
(balanced equation showing formation of a ring scores both marks)	1
isomerisation	suitable balanced equation
The processed products are:		1
·	used in fuels/used in petrol
·	better /more efficient fuels/increase octane number/rating
·	alkenes (from cracking) produce polymers/alcohols
·	H_2 used for Haber process/fuels/hydrogenation of oils	3
QWC		SPAG - look for two complete sentence that present a	1
coherent argument
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7.	1st bullet
	product: CH_3CH_2CHBrCH_2Br (1)
equation: CH_3CH_2CH=CH_2 + Br_2 ® CH_3CH_2CHBrCH_2Br (1)
	products: CH_3CH_2CHBrCH_3 and CH_3CH_2CH_2CH_2Br (1)
(or statement that 2-bromo- is formed)
equation: CH_3CH=CHCH_3 + HBr ® CH_3CH_2CHBrCH_3 (1)
(i.e. for one product)
	products: CH_3CH_2CHOHCH_3 and CH3CH2CH2CH2OH (1)
(or statement that 2-ol is formed)
equation: CH_3CH=CHCH_3 + H_2O ® CH_3CH_2CHOHCH_3 (1)
(i.e. for one product)	6
 
	2nd bullet
	 
1 mark for skeleton with two repeat units (1)
1 mark for correct groups on side chains (1)	2

	3rd bullet
	two (1) (1) from
energy from incineration
development of biodegradable polymers
cracking of waste polymers	2
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Paddington Academy