Edexcel Jan 2016 (IAL) Paper 2 Q21 (with explained solutions) |

Skip to content

Edexcel Jan 2016 (IAL) Paper 2 Q21

Answers available below

SECTION B Answer ALL the questions. Write your answers in the spaces provided. 21 Cyclopentene is a cyclic alkene and cyclopentanol is a cyclic alcohol. (a) Some reactions involving cyclopentene and cyclopentanol are shown in the flowchart. Complete the displayed formulae in the boxes to show the compounds A, B and C, which are the organic products of the reactions. (3) H H cyclopentanol K2Cr2O7(aq) with H2SO4(aq) heat under reflux H H cyclopentene H2(g) with Ni(s) catalyst Br2(l) compound A compound B compound C 10 *P46938A01024* D O N O T W R I T E I N T H I S A R E A D O N O T W R I T E I N T H I S A R E A D O N O T W R I T E I N T H I S A R E A<br />
(b) Give the colour change that would be observed in the reaction between liquid bromine, Br2, and excess cyclopentene. Fromto(c) Bromocyclopentane reacts when heated with aqueous sodium hydroxide solution, according to the following equation. CH2 CH2 H2C CH2 + NaOH H2C CH2 + NaBr H2C CHBr H2C CHOH (i) Complete the mechanism for this reaction on the following diagram. Use curly arrows where necessary and show any relevant dipoles. (1) (3) CH2 CH2 H2C CH2 H2C CH2 +H2C Br H2C CHOH HO (ii) Classify both the type of reaction and mechanism shown in (c)(i). (2) Type of reaction:Mechanism:(iii) What type of bond fission occurs in this reaction? (1)(Total for Question 21 = 10 marks) A E R A S I H T N I E T I R W T O N O D A E R A S I H T N I E T I R W T O N O D A E R A S I H T N I E T I R W T O N O D *P46938A01124* 11 Turn over<br />

Show answer

Section B Acceptable Answers Question Number 21 (a) Reject Mark Compound A (1) Compound B (1) Compound C (1) Max 2 if any H atoms are missing from one or more structures ALLOW Correct rotated structures CH2 un-displayed<br />
Mark Mark Acceptable Answers Reject Just red for the initial colour (From) Orange OR brown ALLOW Shades of orange or yellow or brown including red-brown/reddish-brown OR red if used as a qualifier for a correct colour (To) Colourless IGNORE Clear Both colours are needed for the mark Acceptable Answers Reject Br Br First markM1: Curly arrow from anywhere* on the OH ion to C atom of CBr bond and dipole shown on CBr bond, C+ and Br IGNOREon OH ion (1) Second markM2: Curly arrow from the CBr bond to the Br atom (1) (1) Third markM3: Br as the co-product IGNORE intermediates or transition states even if incorrect *If lone pair of e is shown on the H of the OH ion, no M1 Just Br NaBr / Na+Br/ HBr Question Number 21 (b) Question Number 21 (c)(i)<br />
Acceptable Answers Question Number 21 (c)(ii) (Type of reaction) substitution (1) Reject Mark Acceptable Answers Heterolytic (fission) NOTE Spelling does not have to be 100% accurate, so long as the meaning is clear Reject Homolytic Mark (Total for Question 21 = 10 marks) IGNORE hydrolysis (Mechanism) nucleophilic (1) ALLOW These words in either order or on one line Just SN1 or SN2 scores 1 (Otherwise IGNORE SN1 or SN2 if given with correct answer(s)) NOTE Spelling does not have to be 100% accurate, so long as the meaning is clear Question Number 21 (c)(iii)<br />
Reject Mark No M2 mark if more than one repeat unit shown Question Number 22 (a) Acceptable Answers CN H CN CN H ALLOW CN for CN throughout IGNORE connectivity to the CN / CN group First markM1: Two n in the equation and a correct formula (molecular or structural or displayed) for propenenitrile on LHS of the equation LHS n must be to left of the monomer RHS n must be a subscript IGNORE Any square or round brackets around monomer on LHS (1) Second markM2: One correct displayed repeat unit (with or without a bracket or n shown in the equation) (1) Third markM3: Continuation bond at each end of the repeat unit (with or without a bracket or n shown in the equation) (1) NOTE M3 is awarded for the two continuation bonds, even if the repeat unit given is incorrect Polymer containing a C=C scores max (1) Additional comment Mark the three scoring points independently<br />

Question 21 22 23 24

About us | Need Help? | Feedback

Proudly powered by WordPress | Theme: Sydney by aThemes.