Reactions Of Alcohols

Question 1

Combust

Answer 1

Adds oxygen
Turns into CO2 and H2O
Complete combustion

Question 2

Chlorination

Answer 2

Vigorous, exothermic
Tests for OH group
Makes halogenoalkane
Fast, irreversible
Uses PCl5:
R-OH + PCl5 -> R-Cl + HCl (Steamy fumes) + POCl3

Question 3

Dehydration

Answer 3

Removing water; takes OH and H from adjacent carbon atoms (could have isomers)
Heat with concentrated H3PO4 (phosphoric acid)
Nucleophilic elimination
Opposite of hydration of alkenes

Question 4

Oxidation (general)

Answer 4

Acidified H2SO4|NaCr2O7 (sodium dichromate; could also use potassium dichromate)
14H+ + 6e- + Cr2O7^(2-) -> 2Cr^(3+) + 7H2O
Orange -> green
Different classes of alcohol react differently

Question 5

Oxidation of primary alcohols

Answer 5

Forms aldehyde
Continued oxidation forms carboxylic acid

Question 6

Oxidation of secondary alcohols

Answer 6

Oxidises to ketone

Question 7

Oxidation of tertiary alcohols

Answer 7

DO NOT OXIDISE
So this is the test for tertiary alcohols (no colour change observed)