C13- Halogenoalkanes

Question 1

What bonds do halogenoalkanes have and why?

Answer 1

Polar bonds due to the large difference in electronegativity having charged regions.

Question 2

What is a nucleophiles?

Answer 2

‘Positive liking’ they contain a lone pair of electron attracted to positive region of molecule.

Question 3

What conditions required to make halogenoalkane -> alcohol or amine?

Answer 3

Add NaOH or NH3

Question 4

What is the difference when breaking Cl and I?

Answer 4

Greater the Mr the lower the bond enthalpy so can be broken more easily.

Question 5

What is an Elimination Reaction and the conditions?

Answer 5

Halogenoalkane-> Alkene
High temperature under alcoholic conditions

Question 6

What is Ozone Depletion ?

Answer 6

Ozone in the atmosphere absorbs UV radiation. CFC also absorb UV radiation and break down to form free radicals that catalyse the depletion of the atmosphere

Question 7

What are the reactions of ozone depletion?

Answer 7

O3 + Cl. -> .OCl + O2
.OCl + O3 -> 2O2 + Cl.
2O3 -> 3O2

Question 8

What is the chlorination of alkanes?

Answer 8

Alkanes react with UV light to form halogenoalkanes. The UV light breaks them down forming free radicals.

Question 9

What is included in the initiation?

Answer 9

Cl2 -> 2Cl.

Question 10

Propagation

Answer 10

Cl. + CH4 -> .CH3 + HCl
.CH3 + Cl2 -> CH3Cl + Cl.

Question 11

Termination

Answer 11

.CH3+ .CH3 -> C2H6
Cl. +Cl. -> Cl2
Cl* + *CH₃ → CH3Cl