Explain why the indicated C―C bond in butan-2-ylium is shorter than the indicated C―C bond in butane.

Determine whether the σ bond or the π bond has the more effective orbital overlap in a carbon—carbon double bond.

Sort the indicated bond lengths from shortest to longest.

Determine the number of s bond orbitals that can overlap with the empty p orbitals in the given compound.

Predict which of the following bonds will be longer and which will be stronger.

• C—F or C—Br

Determine the number of s-orbitals that can overlap with the vacant p-orbital in the following ions:

(i) tert-butyl cation

(ii) n-pentyl cation 

(iii) sec-pentyl cation