Write balanced equation for the following reactions to take place:

(i) Catalytic hydrogenation of ethyne.

(ii) Preparation of ethyne from ethylene dibromide.

(iii) Preparation of ester using carboxylic acid.

(iv) Reaction of sodium with ethanol.

(v) Preparation of ethene using alkylhalide

(i) Catalytic hydrogenation of ethyne.

$\underset{\text{ Ethyne}}{\text{C}$2\text{H}2} + \text{H}2 \xrightarrow[300\degree\text{C}]{\text{Nickle}} \underset{\text{ ethene [ethylene]}}{\text{H}2\text{C}=\text{C}\text{H}2} + \text{H}2 \xrightarrow[300\degree\text{C}]{\text{Nickle}} \underset{\text{ethane}}{\text{C}2\text{H}6}

(ii) Preparation of ethyne from ethylene dibromide.

$\text{C}$2\text{H}4\text{-Br}2 + \underset{\text{ alcoholic }}{2\text{KOH}} \xrightarrow{\text{boil}} \text{C}2\text{H}2 + 2\text{KBr} + 2\text{H}2\text{O}

(iii) Preparation of ester using carboxylic acid.

$\underset{\text{ethyl alcohol}}{\text{C}$2\text{H}5\text{OH}} + \underset{\text{acetic acid}}{\text{CH}3\text{COOH}} \xrightarrow{\text{Conc. H}2\text{SO}4} \underset{\text{ester - ethyl ethanoate}}{\text{CH}3-\text{COO}-\text{C}2\text{H}5} + \text{H}_2\text{O}

(iv) Reaction of sodium with ethanol

$\underset{\text{ ethanol} }{2\text{C}$2\text{H}5\text{OH}} + 2\text{Na} \longrightarrow \underset{\text{ sodium ethoxide} }{2\text{C}2\text{H}5\text{ONa}} + \text{H}_2

(v) Preparation of ethene using alkylhalide

$\underset{\text{ Bromoethane [ethyl bromide]}}{\text{C}$2\text{H}5\text{-Br}} + \underset{\text{ alcoholic KOH}}{\text{KOH}} \xrightarrow{\text{boil}} \underset{ \text{ ethene [ethylene]} } {\text{H}2\text{C}=\text{C}\text{H}2} + \text{KBr} + \text{H}_2\text{O}