13.3 - Elimination reactions in halogenalkanes

Question 1

What are the favouring conditions for a substitution reaction?

Answer 1

• hydroxide ions at room temperature (dissolved in water - aqueous)

Question 2

Type of halogenoalkanes (primary, secondary, tertiary):

Answer 2

Question 3

Isomeric products of halogenoalkanes:

Answer 3

Question 4

What are the favouring conditions for elimination?

Answer 4

• hydroxide ions at high temperature (dissolved in ethanol)

Question 5

How do elimination reactions work? (example of OH- ion):

Answer 5

under different conditions, OH- ion can act as a base
removes a H+ ion from the halogenoalkane
an elimination reaction rather than a substitution

Question 6

How to determine whether it’s a substitution or elimination reaction?

Answer 6

Question 7

What happens to CFCs in the atmosphere (what HCFCs are being used):

Answer 7

• they decompose to give chlorine atoms
  —>this decomposes ozone (O3) in the stratosphere (caused a hole)
• HCFCs such as CF3CHCl2 are being used
  —>a lot remain in the atmosphere