4.2 ALCOHOLS & HALOALKANES

Question 1

State what determines primary,secondary and tertiary name for alcohols

Answer 1

• the number of carbons that the carbon of the OH group is on

Question 2

State the three properties of alcohols

Answer 2

1) Soluble due to polar OH group but decreases with chainlength
2) MP/BP increases with chainlength and is higher than alkanes due to hydrogen bonding
3) Volatility decreases with chainlength as there are more hydrogen bonds to overcome

Question 3

State the four typical reactions of alcohols

Answer 3

1) Combustion of alcohols
2) Dehydration of alcohols (forms alkenes) (conditions = H₃PO₄ at 170°C)
3) Halide substitution of alcohols (forms haloalkane) (conditions = H₂SO₄ with NaBr)
4) Oxidation of primary and secondary alcohols (conditions = acidified potassium dichromate with reflux/distill)

Question 4

Reaction/conditions of oxidation of primary,secondary and tertiary alcohols and colour change

Answer 4

(and water is also always formed)

Question 5

Reaction/conditons for combustion of alcohols (ethanol)

Question 6

Reactions/conditions for dehydration of alcohols (ethanol)

Question 7

Reaction/conditions for halide substitution of alcohols (ethanol)

Question 8

State what determines primary,secondary and tertiary name for haloalkanes

Answer 8

• the number of carbons that the carbon of the halide group is on

Question 9

State the two typical haloalkane reactions

Answer 9

1) Hydrolysis of haloalkanes (forms alcohol) (conditions = aqueous NaOH)
2) Percipitation of haloalknes (forms coloured silver halides) (conditions = silver nitrate and ethanol)

Question 10

Reaction/conditions/mechanism for hydrolysis of haloalkanes (bromoethane)