(a) Write an equation for the laboratory preparation of

(i) An unsaturated hydrocarbon from calcium carbide.

(ii) An alcohol from ethyl bromide.

(b) What would you see, when ethyne is bubbled through a solution of bromine in carbon tetrachloride?

(c) Name the addition product formed between ethene and water.

(a) (i) Ethyne [C₂H₂] from Calcium Carbide :

$\underset{\text{calcium carbide}}{\text{CaC}$2} + \underset{\text{water}}{2\text{H}2\text{O}} \longrightarrow \underset{\text{ethyne}}{\text{C}2\text{H}2} ↑ + \underset{\text{calcium hydroxide}}{\text{Ca(OH)}_2}

(ii) An alcohol from ethyl bromide.

$\underset{\text{ Bromoethane [ethyl bromide]}}{\text{C}$2\text{H}5\text{-Br}} + \text{KOH [aq.]} \xrightarrow{\text{boil}} \underset{ \text{ ethyl alcohol}} {\text{C}2\text{H}5\text{OH}} + \text{KBr}

(b) Brown colour of bromine disappears when ethyne is bubbled through a solution of bromine in carbon tetrachloride.

C₂H₂ + Br₂ ⟶ C₂H₂Br₂ + Br₂ ⟶ C₂H₂Br₄

(c) Ethanol (C₂H₅OH)

C₂H₄ + H₂O ⟶ C₂H₅OH