# Question #41939

Feb 11, 2017

$\text{(i)}$ ${\text{H"_2"C=CH"_2 + "H"_2 rarr"H"_3"C-CH}}_{3}$

#### Explanation:

And this is a (simple?) hydrogenation reaction.

For methane and chlorine, normally we would invoke photolysis:

$\text{(ii)}$ $\text{CH"_4 + "Cl"_2 +hnu rarr "H"_3"CCl" + "HCl}$

Possibly, you would get a mess under conditions of thermolysis.

The last rxn is a substitution process:

$\text{(iii) " "H"_3"CC""H"_2"Br(l)" "+ KOH(aq)" rarr "H"_3"CCH"_2"OH(l)" "+ KBr(s)} \downarrow$

The deposition of potassium bromide, a stable salt, provides a thermodynamic driving force to the reaction.