(a) A carbon compound X is a good solvent. On reaction with sodium, X forms two products Y and Z. Z is used to convert vegetable oil into vegetable ghee. Identify and name X, Y and Z. Also write the equation of reaction of X with sodium to justify your answer.

(b) Write chemical equation to show what happens when ethanol :

1. burns in oxygen/air.
2. is heated at 443 K in excess conc. H₂SO₄.
3. reacts with acidified potassium dichromate.

(a)

• X = Ethanol (C₂H₅OH) — a good solvent.
• Y = Sodium ethoxide (C₂H₅ONa).
• Z = Hydrogen gas (H₂) — hydrogen is used for hydrogenation to convert vegetable oil into vegetable ghee.

Reaction with sodium :

$2\text C$2 \text H5 \text {OH} + 2\text {Na} \longrightarrow 2\text C2 \text H5 \text {ONa} + \text H_2(\uparrow)

(b)

1. Combustion of ethanol : Ethanol burns in air to form carbon dioxide and water, releasing heat and light which shows ethanol acts as a clean fuel.

Chemical equation :

$\text C$2 \text H5 \text {OH} + 3\text O2 \longrightarrow 2\text {CO}2 + 3\text H_2 \text O

2. Dehydration of ethanol (443 K, conc. H₂SO₄) : When ethanol is heated with concentrated sulphuric acid, it loses a water molecule and forms ethene, an unsaturated hydrocarbon.

Chemical equation :

$\text C$2 \text H5 \text {OH} \xrightarrow [443 \text K]{\text {conc.} \text H2 \text {SO}4} \text C2 \text H4 + \text H_2 \text O

3. Oxidation by acidified potassium dichromate : Ethanol is oxidised to ethanoic acid by acidified potassium dichromate, with the solution’s colour changing from orange to green.

Chemical equation :

$\text C$2 \text H5 \text {OH} \xrightarrow {\text {acidified } \text K2 \text {Cr}2 \text O7} \text {CH}3 \text {COOH}