1.
State what is meant by a homologous series.
[1 mark]
- same functional group, differ by CH₂
JD SCIENCE
Module 4 Core organic chemistry
Indicative marking points. Award marks for equivalent scientific or mathematical wording. Do not issue this sheet with the student worksheet.
2.
State what is meant by isomerism.
[1 mark]
- same molecular formula, different structure
3.
State what is meant by a nucleophile.
[1 mark]
- electron-pair donor
4.
State what is meant by an electrophile.
[1 mark]
- electron-pair acceptor
5.
State what is meant by free-radical substitution.
[1 mark]
- alkanes + halogens in UV
6.
State what is meant by electrophilic addition.
[1 mark]
- alkenes + Br₂ / HBr
7.
State what is meant by nucleophilic substitution.
[1 mark]
- haloalkanes + OH⁻
8.
State what is meant by oxidation of alcohols.
[1 mark]
- primary → aldehyde → carboxylic acid; secondary → ketone
9.
State what is meant by a carbonyl test.
[1 mark]
- Brady's / 2,4-DNP orange ppt
10.
State what is meant by optical isomerism.
[1 mark]
- chiral carbon, four different groups
11.
Grace is asked about a homologous series in a OCR Chemistry paper.
(a) [2 marks]
- gradual change in physical properties
(b) [3 marks]
- same general formula
12.
Grace is asked about isomerism in a OCR Chemistry paper.
(a) [2 marks]
- structural and stereoisomerism
(b) [3 marks]
- E–Z and optical
13.
Grace is asked about a nucleophile in a OCR Chemistry paper.
(a) [2 marks]
- OH⁻, CN⁻, NH₃
(b) [3 marks]
- attacks δ+ carbon
14.
Grace is asked about an electrophile in a OCR Chemistry paper.
(a) [2 marks]
- H⁺, Br⁺ (from Br₂/FeBr₃), NO₂⁺
(b) [3 marks]
- attacks electron-rich centres
15.
Grace is asked about free-radical substitution in a OCR Chemistry paper.
(a) [2 marks]
- initiation, propagation, termination
(b) [3 marks]
- mixture of products
16.
Grace is asked about electrophilic addition in a OCR Chemistry paper.
(a) [2 marks]
- carbocation intermediate
(b) [3 marks]
- Markownikoff
17.
Molecular formula of hexane
[3 marks]
- Final answer: C₆H₁₄
18.
How many structural isomers of C₄H₁₀
[3 marks]
- Final answer: 2
19.
Mr of CH₃COOH
[3 marks]
- Final answer: 60
20.
Moles in 6.0 g of ethanoic acid
[3 marks]
- Final answer: 0.10 mol
21.
A chiral carbon is in CH₃CHBrCH₂CH₃. How many optical isomers
[3 marks]
- Final answer: 2
22.
Percentage yield 7.2 g from theoretical 9.0 g
[3 marks]
- Final answer: 80%
23.
Grace carries out a OCR-style required practical linked to organic chemistry. This is a typical OCR required-practical style question.
(a) [2 marks]
- Independent: the independent variable for this topic
- Dependent: the measured outcome
(b) [2 marks]
- keep all other variables constant
- so the test is fair / only one variable is changed
(c) [2 marks]
- repeat and calculate a mean / use a tighter method
24.
Grace carries out collecting valid data for organic chemistry. This is a typical OCR required-practical style question.
(a) [2 marks]
- Independent: a chosen factor
- Dependent: a quantitative measurement
(b) [2 marks]
- calibrated instrument
- so the test is fair / only one variable is changed
(c) [2 marks]
- systematic error from zero error
25.
Grace carries out drawing a graph for organic chemistry. This is a typical OCR required-practical style question.
(a) [2 marks]
- Independent: x-variable
- Dependent: y-variable
(b) [2 marks]
- same scale / same apparatus
- so the test is fair / only one variable is changed
(c) [2 marks]
- not drawing a line of best fit through the trend
26.
Grace carries out evaluating a method about organic chemistry. This is a typical OCR required-practical style question.
(a) [2 marks]
- Independent: method change
- Dependent: precision / accuracy
(b) [2 marks]
- same sample size
- so the test is fair / only one variable is changed
(c) [2 marks]
- too few repeats
27.
Compare a homologous series with isomerism.
[4 marks]
- same functional group, differ by CH₂
- same molecular formula, different structure
- give one linked difference
28.
Compare isomerism with a nucleophile.
[4 marks]
- same molecular formula, different structure
- electron-pair donor
- give one linked difference
29.
Compare a nucleophile with an electrophile.
[4 marks]
- electron-pair donor
- electron-pair acceptor
- give one linked difference
30.
Compare an electrophile with free-radical substitution.
[4 marks]
- electron-pair acceptor
- alkanes + halogens in UV
- give one linked difference
31.
Apply your knowledge of nucleophilic substitution to this situation: Sn1 or Sn2
[3 marks]
- Sn1 or Sn2
32.
Apply your knowledge of oxidation of alcohols to this situation: acidified dichromate
[3 marks]
- acidified dichromate