Give balanced chemical equations for the preparation of :

(i) Ethene from bromoethane

(ii) Ethyne using calcium carbide

(iii) Methane from sodium acetate.

(i) Ethene from bromoethane

$\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}

(ii) Ethyne from calcium carbide

$\underset{\text{calcium carbide}}{\text{CaC}$2} + \underset{\text{cold water}}{2\text{H}2\text{O}} \longrightarrow \underset{\text{ethyne [acetylene]}}{\text{C}2\text{H}2} + \text{Ca(OH)}_2

(iii)

$\underset{\text{ sodium acetate}}{\text{CH}$3\text{.COONa}} + \underset{\text{sodalime}}{\text{NaOH}} \underset{\Delta}{\xrightarrow{\text{CaO}}} \underset{\text{methane}}{\text{C}\text{H}4} + \text{Na}2\text{CO}3