Explanation

(a)
Chloroform $(CHCl_{3})$ is formed on reaction of ethyl alcohol with bleaching powder. The reaction is complex and takes place in the following steps
$(i)\ CaOCl_{2}\ \ + \ \ H_{2}O\ \rightarrow \ \ Ca(OH)_{2}\ \ + \ \ Cl_{2}$
bleaching
powder
$(ii)\ CH_{3}CH_{2}OH\ \ + \ \ Cl_{2}\ \ \rightarrow \ \ \ CH_{3}CHO\ \ + \ \ 2HCl\$
oxidation step
$(iii)\ CH_{3}CHO\ \ + \ \ 3Cl_{2}\ \ \rightarrow \ CCl_{3}CHO\ \ + \ \ 3HCl$
chloral
chlorination step
(iv) [image:10_image92.emf]