Thus, the stability of carbocations decreases in the order : II > I > III.

The process of separation of a racemic mixture into $$d-$$ or $$l-$$ forms (enantiomers) is called resolution. The racemic mixture of enantiomers is resolved by treating with an enantiomers of some chiral compound. The products are diastereomers which can be separated by usual methods such as recrystallisation, chromatography, etc.

The structure of 2-methyl-2-butene is

Hyperconjugation occurs through the $$H$$ - atoms present on the carbon atom next to the double bond i.e. $$\alpha $$ - hydrogen atoms.
There is no $$\alpha - H$$  in the structures I and II.
So, hyperconjugation occurs in structure III only i.e.

No explanation is given for this question. Let's discuss the answer together.

Phenoxide ion shows maximum resonating structures.

 will not show $$cis-trans$$    isomerism because double bonded carbon atom have two same groups ( $$ - C{H_3},$$  methyl group ).

NOTE: This is an example of \[{{S}_{N}}1\]  reaction involving carbocation as intermediate.

This carbocation is especially stabilised through resonance in which \[-\underset{\centerdot \,\centerdot }{\overset{\centerdot \,\centerdot }{\mathop{O}}}\,-C{{H}_{3}}\]   group acts as a good electron donor.

The organic substance being more soluble in organic solvent is transferred from aqueous layer to the organic layer.