3.3.3.1 Nucleophilic Substitution

Question 1

What is a nucleophile?

Answer 1

An electron pair donor

Question 2

Why is a carbon in a C-X bond susceptible to attack from nucleophiles?

Answer 2

It is electron deficient due to the X being more electronegative than the carbon

Question 3

What are the 3 types of nucleophiles?

Answer 3

:-OH
:-CN
:NH3

Question 4

Describe the nucleophilic substitution by hydroxide ions

Answer 4

Reagent: Aqueous KOH/NaOH
Condition: Reflux gently
Mechanism: Nucleophilic substitution
Product: Alcohol
Overall equation: R-X +-OH -> R-OH +-X

Question 5

What is hydrolysis?

Answer 5

Nucleophilic substitution by hydroxide ions. It is the breaking of chemical bonds with water but also applied when OH- ions are used

Question 6

What does the rate of nucleophilic substitution depend on?

Answer 6

The ease if breaking the C-X bond

Question 7

Describe nucleophilic substitution by cyanide ions

Answer 7

Reagent: Aqueous solution of potassium cyanide
Condition: Reflux gently
Mechanism: Nucleophilic substitution
Product: Nitrile
Overall equation: R-CH2X +KCN -> R-CHCN +KX

Question 8

Why is the nucleophilic substitution by cyanide ions important?

Answer 8

A carbon atom is added to the chain - meaning that the length of the chain increases by one atom. This is useful in organic synthesis where the reactant has one less carbon than the product.

Question 9

Describe nucleophilic substitution by ammonia ions

Answer 9

Reagent: Excess of concentrated ammonia solution
Condition: Sealed under pressure
Mechanism: Nucleophilic substitution
Product: Amine
Overall equation: R-X +2NH3 -> R-NH2 + NH4