Which of the following are correct?
Four structures are given in options (a) to (d). Examine them and select the aromatic structures.
The molecules having dipole moment are ............. .
Why do alkenes prefer to undergo electrophilic addition reaction while arenes prefer electrophilic substitution reactions? Explain.
Alkenes are rich source of loosely held pi $(\pi)$ electrons, due to which they show electrophilic addition reaction. Electrophilic addition reaction of alkenes are accompanied by large energy changes so these are energetically favourable than that of electrophilic substitution reactions. In special conditions alkenes also undergo free radical substitution reactions.
In arenes during electrophilic addition reactions, aromatic character of benzene ring is destroyed while during electrophilic substitution reaction it remains intact. Electrophilic substitution reactions of arenes are energetically more favourable than that of electrophilic addition reaction.
That's why alkenes prefer to undergo electrophilic addition reaction while arenes prefer electrophilic substitution reaction.
Alkynes on reduction with sodium in liquid ammonia form trans alkenes. Will the butene thus formed on reduction of 2 - butyne show the geometrical isomerism ?
Trans-2-butene formed by the reduction of 2-butyne is capable of showing geometrical isomerism.
