Question

Select a compound from each of the following set having the properties as indicated.
(a) Isopentane, n-pentane &neopentane ; having lowest boiling point.
(b) Benzene, n-hexane &ethyne; having maximum acidic character.
(c) Nitrobenzene, hydroxybenzene& methylbenzene; meta-directing group on benzene ring.​

Answer 1

Answer:

(a)  Neopentane

Increase in no of branching decreases the surface area which decreases the van  der waal's force thus decreasing the boiling point.

(b) Ethyne

Increase in electronegativity increases acidic character . Here,  ethyne is most electronegative compound (because of sp hybridisation of ethyne which is more electronegative than sp2 and sp3.)

(c) Nitrobenzene

As nitrobenzene is electron deficient it places the approaching electrophile in the meta position.