4.5 - Haloalkanes

Question 1

Define nucleophile

Answer 1

electron pair donor

Question 2

Haloalkane to alcohol

Answer 2

NaOH (aq)
nucleophilic substitution

Question 3

How does strength of carbon-halogen bond affect rate of hydrolysis?

Answer 3

weaker carbon-halogen bond = faster rate of hydrolysis
strongest to weakest: C-F, C-Cl, C-Br, C-I

Question 4

What measurement should you take to compare the rates of hydrolysis?

Answer 4

time for ppt to appear

Question 5

Equation for breakdown of ozone (how ozone layer is maintained)

Answer 5

O2 + O ⇌ O3

Question 6

Equation for breakdown of CFCs to radicals

Answer 6

CF2Cl2 -> CF2Cl* + Cl*
requires UV

Question 7

Mechanism for breakdown of ozone

Answer 7

Propagation: Cl* + O3 -> ClO* + O2
ClO* + O -> Cl* +O2
Overall: O3 + O -> 2O2

Question 8

Mechanism for formation of NO

Answer 8

NO* + O3 -> NO2* + O2
NO2* + O -> NO* + O2
Overall: O3 + O -> 2O2

Question 9

Describe how life on Earth benefits from an ozone layer

Answer 9

• ozone absorbs UV
• UV at Earth’s surface is reduced

Question 10

State 2 sources of nitrogen oxides in the atmosphere

Answer 10

thunderstorms
aircraft

Question 11

How can haloalkanes be hydrolysed in a substitution reaction?

Answer 11

• in alkali (aq)
• H2O in presence of AgNO3 + ethanol (to compare rates of hydrolysis in C-X bonds)