Which of the following explains the greater stability of a tertiary butyl carbocation compared to a
secondary butyl carbocation?

1. + R effect of ${CH}_3$ groups 

2. $-$R effect of $-$ CH₃  groups 

3. Hyperconjugation 

4. $-$l effect of $-$CH₃ groups 

The most stable carbocation among the following is:

1.		2.
3.		4.

Which of the following compounds gives the most stable carbocation on ionization of its C–Cl bond?

1.		2.
3.		4.

The most reactive compound towards electrophilic reagent among the following is:

1.		2.
3.		4.

Which amongst the following is the most stable carbocation:
 

1.		2.
3.		4.