Halogenoalkanes exam q

Question 1

A molecule of CFC-11 breaks down in the upper atmosphere to form a chlorine free radical.
Give the equation for this reaction. 2 marks
formula of cfc-11 is CCl3F

Answer 1

CCl3F → *CCl2F + *Cl
radical dot anywhere on each radical

Question 2

State the benefit to life on Earth of ozone in the upper atmosphere. 1 mark

Answer 2

Absorbs harmful uv rays

Question 3

Suggest one reason why the use of CFCs was not restricted until several years after Rowland and Molina published their research.

Answer 3

• lack of evidence that ozone was being depleted
• lack of alternatives to CFCs
• commercial interest to continue to use CFCs
• hard to obtain international agreement

Question 4

CFC-11 is a greenhouse gas that can contribute to global warming.
State and explain how CFC-11 is able to contribute to global warming.

Answer 4

absorbs infrared radiation
M1 idea of IR being taken in
M2 molecule has polar bonds

Question 5

Which compound is not formed by reacting 3-bromo-3-methylhexane with warm,
ethanolic potassium hydroxide?
A 2-ethylpent-1-ene
B 3-methylhex-1-ene
C 3-methylhex-2-ene
D 3-methylhex-3-eneWhich

Answer 5

B