haloalkanes

Question 1

Allyl bromide is a member of a homologous series. Compounds in this series have the same
general formula.
(i) What is meant by the term homologous series?
(ii) What is the general formula of the homologous series that has allyl bromide as a
member?
(iii) Give the systematic name for allyl bromide.

Answer 1

(i) (series of compounds with the) same functional group
OR same/similar chemical properties
OR same/similar chemical reactions
(ii)
CnH2n–1Br
(iii) 3-bromoprop(-1-)ene

Question 2

What does a curly arrow represent in mechanisms?

Answer 2

Movement of an electron pair

Question 3

What is meant by the term nucleophile?

Answer 3

Electron pair donor

Question 4

Answer 4

Question 5

Radical substitution produces a mixture of organic products.
Suggest two reasons why.

Answer 5

further substitution
OR
produces different termination products
OR
More than one termination step


substitution at different positions along chain


Question 6

Explain why 1-iodopropane is hydrolysed faster than 1-bromopropane.

Answer 6

C–I bonds broken more easily


C–I bonds are weaker OR have less bond enthalpy OR C–I
bonds are longer


Question 7

Chlorofluoroalkanes, CFCs, were developed from fluoroalkanes and were used in aerosols
and as refrigerants. Under the Montreal Protocol, CFCs are now largely banned because of
their ozone-depleting properties. CFCs have now been replaced in many applications.
Suggest two reasons why there is still concern about ozone depletion.

Answer 7

Any TWO from:
CFCs take many years to reach the ozone layer OR long
residence time

CFCs are still being used


there are other ozone depleting substances
