Effect Of Nucleophile

Question 1

Why is the nature of the nucleophile not important for SN1 reactions?

Answer 1

This is because it does not affect the rate as the nucleophile is not involved in the rate determining step (2 step)

Question 2

Why is the nature of the nucleophile important for SN2 reactions?

Answer 2

This is because it does affect the rate as the nucleophile is involved in the rate determining step (1 step)

Question 3

Describe the effect of concentration and strength of nu on rate or SN2

Answer 3

Increasing the strength and concentration will increase the rate as it is part of the rate determining step

Question 4

How does concentration strength affect SN1 reactions?

Answer 4

The products of the SN1 reaction can be affected by concentration of Nu
A high concentration of strong conc can react more rapidly than low concentration

Question 5

How will secondary halogenoalkane react with a nucleophile of high concentration?

Answer 5

It is likely to react in an SN2 reaction than an SN1

Question 6

What are the general trends of nucleophilicity?

Answer 6

• negatively charged are stronger than neutral
• nuclephilicity decreasing going to the right on the stable as electronegative elements tend to hold onto their electrons more tightly
• nucleophilicity increases going down the group as polarisability increases

Question 7

Why do aprotic solvents enhance nucleophilicity compared to polar protic?

Answer 7

Aprotic solvents do not solvate nucleophiles whereas protic solvents do hence reducing their reactivity

Question 8

If conditions are dilute, what mechanism does this suggest?

Answer 8

This suggests SN1