1. Alcohols Preparations and Chemical Properties:

2. Oxidation Reactions of Alcohols

Summary of Oxidation:

	Reagent/Alcohol	${C H}_{3} {C H}_{2} O H$
(1)	$P C C$ or $P D C$	${C H}_{3} C H O$	$X$
(2)	${C r O}_{3}$ in ${C H}_{2} {C l}_{2}$ Solvent	${C H}_{3} C H O$	$X$
(3)	$C u / △$	${C H}_{3} C H O$
(4)	${K M n O}_{4} {/ H}^{+}$	${C H}_{3} C O O H$	$X$
(5)	$K_{2} {C r}_{2} O_{7} {/ H}_{2} S O_{4}$	${C H}_{3} C O O H$	$X$
(6)	${C r O}_{3}$ in water	${C H}_{3} C O O H$	$X$

Note: $M n O_{2}$ is a regioselective reagent for the oxidation of only allylic and benzylic alcohols into their respective carbonyl compounds.

3. Physical Properties

(i) Nature of alcohol:

(a) Alcohols are poisonous in nature. Its poisonous character increases with the increment in molecular mass or branching. Ethanol is an exception, which is non-poisonous in nature. Methanol causes blindness.

(b) Isopropyl alcohol is called rubbing alcohol.

(d) Ethanol is a liquid while glucose is a solid due to more intermolecular $H$ -bonding in glucose.

(e) Alcohols are neutral substances towards the litmus paper test.

(f) Lower members containing up to $12$ carbon atoms are liquids.

(g) The higher members are solids and are almost odourless.

(h) They have a distinctive smell and a burning taste.

(ii) Boiling point:

(a) Boiling point ∝ Molecular mass $\propto \frac{1}{N u m b e r o f b r a n c h e s}$

(b) The boiling point of alcohols in water increases as the extent of hydrogen bonding increases.

(c) The boiling point of alcohols are higher than ethers of comparable molecular masses as intermolecular hydrogen bonding is present in alcohols.

(d) Order of Boiling point:

${C H}_{3} O H < {C H}_{3} {C H}_{2} O H < {C H}_{3} {C H}_{2} {C H}_{2} O H$

(iii) Solubility in water:

(a) The lower alcohols are soluble in water, and the solubility diminishes as the molecular mass increases.

Solubility $\propto \frac{1}{M o l e c u l a r m a s s} \propto$ Number of branches

(b) Their solubility in water is to be expected since the oxygen atom of the hydroxyl group in alcohols can form hydrogen bonds with water molecules.

${C H}_{3} O H > {C H}_{3} {C H}_{2} O H > {C H}_{3} {C H}_{2} {C H}_{2} O H$

4. Differences between Primary, Secondary, and Tertiary Alcohols:

Oxidation method:

(i) Dichromate test:

(a) $1^{\circ} - a l c o h o l \overset{H^{\oplus} {/ K}_{2} {C r}_{2} O_{7}}{\underset{o r a n g e [{C r}^{+ 6}]}{\to}} a l d e h y d e + {C r}^{+ 3} [green color]$

(b) $2^{\circ} - a l c o h o l \overset{H^{\oplus} {/ K}_{2} {C r}_{2} O_{7}}{\underset{o r a n g e [{C r}^{+ 6}]}{\to}} k e t o n e + {C r}^{+ 3} [g r e e n c o l o u r]$

(c) $3^{\circ} - a l c o h o l \overset{H^{\oplus} {/ K}_{2} {C r}_{2} O_{7}}{\underset{o r a n g e [{C r}^{+ 6}]}{\to}} N o o x i d a t i o n [No green colour]$