Alkenes - DF

Question 1

Alkenes are saturated or unsaturated and why

Answer 1

unsaturated as it contains a double bond (C=C)

Question 2

What functional group would a compound with a C=C be

Answer 2

alkene

Question 3

Shape of alkene - ethene

Answer 3

shape around the double bond is planar triangular as 3 sets of electrons around the central atoms repel to get as far away as possible

Question 4

Bonding alkenes

Answer 4

in molecules atoms are covalently bonded and the shared pair of electron exist in a molecular orbital

Question 5

What are the 2 main types of molecular orbital (2 main types of covalent bond)

Answer 5

sigma bond (σ) and pi bond (𝛑)

Question 6

Sigma bond (σ) definition

Answer 6

the shared pair of electrons is directly between the 2 nuclei. Sigma bonds are the strongest type of covalent bond. All single bonds (and the first part of double/tripe bonds) are sigma bonds

Question 7

How many sigma bonds are in propene?

Answer 7

8 - 7 single bonds and 1 first part of the double bond

Question 8

Pi bond (𝛑) definition

Answer 8

the second part of a double or 2/3 part of a triple bond is a pi bond. As electrons are not directly between 2 nuclei a pi bond is weaker than a sigma bond. The pi bond breaks when an alkene reacts