Sigma, Pi Bonds

Question 1

What is a sigma bond?

Answer 1

A covalent bond formed by the linear overlap of atomic orbitals.

Question 2

What is a pi bond?

Answer 2

A covalent bond formed by the sideways overlap of p orbitals.

Question 3

What does a C=C bond consist of?

Answer 3

A C=C bond consists of a sigma (σ) bond and a pi (π) bond.

Question 4

How is the sigma (σ) bond in a C=C bond formed?

Answer 4

The sigma (σ) bond is formed directly between two carbon atoms by the head-on overlap of orbitals.

Question 5

How is the pi (π) bond in a C=C bond formed?

Answer 5

The pi (π) bond is formed above and below the plane of the carbon atoms by sideways overlap of p-orbitals.

Question 6

How many electrons does each carbon atom donate to the σ-bond?

Answer 6

Each carbon atom donates one electron to the electron pair in the σ-bond.

Question 7

How many electrons does each carbon atom donate to the π-bond?

Answer 7

Each carbon atom donates one electron to the electron pair in the π-bond.

Question 8

What is the bond length comparison between C=C and C-C?

Answer 8

The C=C bond has a shorter bond length than the C-C bond.

Question 9

What does bond length refer to?

Answer 9

Bond length is the distance between the nuclei of two covalently bonded atoms.

Question 10

How does the reactivity of alkenes compare to alkanes?

Answer 10

Alkenes are more reactive than alkanes because of the C=C double bond.

Question 11

What is the relationship between the strength of pi bonds and sigma bonds?

Answer 11

The pi bond is slightly weaker than the sigma bond, making it easier to break.