Topic 6 : (Halogenoalkanes)

Question 1

What are Nitriles?

Answer 1

•Organic compounds containing the C-CN group

Question 2

Primary amines

Answer 2

• compounds containing the C-NH2 group

Question 3

Nucleophilic substitution

Answer 3

• Attacking nucleophile replaces an existing atom/group in a molecule

Question 4

Ethanolic solution

Answer 4

• Solution where ethanol is the solvent

Question 5

Elimination reaction

Answer 5

• A Molecule loses atoms attached to adjacent carbon atoms, forming a C=C double bond
• e.g. DEHYDRATION

Question 6

Hydrolysis reaction equation & conditions

Answer 6

RX➝ ROH

• Warm H2O

Question 7

Reaction and conditions to produce alcohol for halogenoalkanes

Answer 7

•Aqueous KOH(aq)
•Heat under REFLUX
RX➝ ROH + KX

Question 8

Production of Nitriles (reaction & conditions)

Answer 8

•Ethanolic potassium cyanide KCN (eth)
•Under REFLUX
RX➝ RCN + KX

Question 9

Production of Amines (Reactions & conditions)

Answer 9

•Excess (Double) Ammonia gas
•Sealed Tube
RX➝ RNH2 + NH4X

Question 10

Elimination reactions for Halogenoalkanes

Answer 10

• KOH(eth) Ethanolic potassium hydroxide

* OH- acts as a base

Question 11

Practical: Rates of Hydrolysis

Answer 11

• This is nucleophilic substitution
• Water acts as the nucleophile
1. Set up 3 Test tubes for each haloalkane each containing 1cm^3 of ethanol and 2 drops of haloalkane
2. Place the test tubes in a water bath (60 C) along with a test tube of 0.1 moldm silver nitrates (let it reach a constant temperature)
3.Quickly add 1cm^3 of silver nitrate to each tube
4.Record the time taken for a precipitate to form

Question 12

Why do precipitates form faster for some halogenoalkanes?

Answer 12

• Bond Enthalpy

* Different structure (tertiary fastest)

Question 13

What is a Nucleophile?

Answer 13

A molecule that has a tendency to donate electrons to an electron deficient area