Reactions Of Halogenoalkanes

Question 1

Making halogenoalkanes:
Through free radical substitution

Answer 1

1. Initiation (UV) - formation of the radical
2. Propagation A and B - reaction of the radical to make a radical
3. Termination - two radicals react

Question 2

Making halogenoalkanes:
Electrophilic addition

Answer 2

Alkene + H-X -> halogenoalkane

Question 3

Making halogenoalkanes:
From alcohols, using PCl5

Answer 3

Fast, exothermic
R-OH + PCl5 -> HCl + R-Cl + POCl3

Question 4

Making halogenoalkanes:
From alcohols, especially tertiary

Answer 4

React with concentrated HCl
Shake
R-OH + HCl -(shake)> R-Cl + H2O

Question 5

Making halogenoalkanes:
From alcohols, making bromides

Answer 5

Use PBr3
Or use NaBr and concentrated H2SO4

Question 6

Making halogenoalkanes:
From alcohols, making iodides

Answer 6

Use PI3
Make it using iodine and red phosphorous

Question 7

Using halogenoalkanes:
Making alcohols using water

Answer 7

R-X + H2O -> ROH + H-X

Question 8

Using halogenoalkanes:
Making alcohols using silver nitrate

Answer 8

R-X + AgNO3(aq) -(ethanol as cosolvent)> R-OH + AgX

Question 9

Using halogenoalkanes:
Making alcohols using aqueous sodium hydroxide (NaOH(aq))

Answer 9

R-X + NaOH(aq) -> R-OH + NaX2
Nucleophilic substitution

Question 10

Using halogenoalkanes:
With sodium hydroxide in ethanol (NaOH(et))

Answer 10

R-X + NaOH(et) -> alkene
Nucleophilic elimination

Question 11

Using halogenoalkanes:
With potassium cyanide (KCN)

Answer 11

R-X + KCN -(ethanol reflex)> R-CN
Used to make other things

Question 12

Using halogenoalkanes:
With ammonia

Answer 12

R-X + NH3 (concentrated, excess) -(heat in sealed test tube)> RNH2