Why are alkyl groups said to be electron releasing compared to hydrogen when talking about carbocations???????
Carbocations are stabilised by alkyl groups. This is because the carbocation is an empty p orbital on the carbon atom. C-H sigma bonds and C-C sigma bonds on the carbon one along from the carbocation can donate some of their electron density into the empty p orbital so it is not as electron deficient. This is called hyperconjugation. Hydrogen doesn’t do this, so there is no electron donation and no stabilisation.
