Sn1 & Sn2

Question 1

Which type of alcohol undergoes SN1

Answer 1

Tertiary alcohols

Question 2

Which type of alcohols undergo SN2

Answer 2

Primary

Question 3

Describe the process of SN2

Answer 3

• A Nucleophile approaches from the opposite side to the C-X bond in “Antiperiplanar” attack.
• Two partial bonds to carbon are formed with he negative charge spread out.
• There is an “inversion” of the arrangement of R-groups around carbon. As the nucleophile bonds.

Question 4

What process do secondary alcohols go through

Answer 4

Either SN1 or SN2

Dont need to know why or which ones

Question 5

Which of the two types of reactions is faster and why?

Answer 5

SN2 is slower than SN1. This is because in SN2 the transition stage requires an extremely high activation energy.

Question 6

How many concentrations does SN2 depend on?

Answer 6

Both concentrations of the reactants hence 2

Question 7

How many concentrations does SN1 depend on

Answer 7

One hence SN 1

Question 8

Describe the process of SN1 mechanism

Answer 8

• First the C-X bond is broken by heterolytic fission to form a carbocation.
• The nucleophile then rapidly attacks the charged carbocation to form a new C-Nu bond.
• the bond can be formed on either side.

Question 9

How does the structure of the molecule taking part in SN1 change

Answer 9

• Original halogenoalkane has a tetrahedral shape but when the carbocation forms it is planar.
• This means there is an equal chance of the Nu attacking from either side so there are 2 products, both are enantiomers and are equal in number forming a racemic mixture.