Question

Describe with diagram the laboratory method of preparation of ethylene. Write its chemical reaction with the following. Also write the relevant chemical equations:
(i) Baeyer's reagent
(ii) Ozone
(iii) Sulphur monochloride
(iv) Chlorine

Answer 1

The dehydration of ethanol in presence of conc sulphuric acid or phosphoric acid gives ethylene.
$C{H}_3-C{H}_2-OH\underset{-H_{2}O}{\overset{conc.H_{2}S{O}_4}{\to }}C{H}_2=C{H}_2$
The reactions of ethylene with:
(i) Baeyer's reagent (cold dilute alkaline $KMn{O}_4$): $C{H}_2=C{H}_2\underset{\Delta }{\overset{alkaline.KMn{O}_4}{\to }}2HCOOH\to 2C{O}_2+2H_2$
(ii) Ozone: $H_{2}C=C{H}_2\underset{2)Zn/H_{2}O}{\overset{1)O_3}{\to }}2HCHO$
(iii) Sulphur monochloride: $2H_{2}C=C{H}_2+S_{2}C{l}_2\to \underset{\text{Mustard gas}}{S(-C{H}_2-C{H}_2-Cl{)}_2}+S$
(iv) Chlorine: $H_{2}C=C{H}_2+SCl\to \underset{\text{1,2-dichloroethane}}{Cl-C{H}_2-C{H}_2-Cl}$