Halogenoalkanes

Question 1

What mechanism is used for :OH, :CN, :NH3

Answer 1

Nucleophilic substitution

Question 2

Nucleophilic sub. conditions of the :CN

Answer 2

• heat under reflux

Question 3

Nucleophilic sub. conditions of the :OH

Answer 3

-Room temp
- Aqueous solution (NahOH)
-Heat under reflux

Question 4

Nucleophilic sub. conditions of the :NH3

Answer 4

• Under pressure

Question 5

Rate of these substitution reactions depends on?

Answer 5

• strength of the C-X bond
• The weaker the bond
  -the easier it is to break and the faster the reaction.

Question 6

Reactivity?

Answer 6

• The more electronegative halogen produces
  a polar bond
• This makes the halogenoalkanes more
  reactive

Question 7

Nucleophilic sub. :OH reagent?

Answer 7

• KOH / NaOH
  -(Role —> Nucleophile).

Question 8

Nucleophilic sub. :CN reagent?

Answer 8

• KCN (dissolved in ethanol/water)
  -(Role —> Nucleophile).

Question 9

Nucleophilic sub. :NH3 reagent?

Answer 9

• NH3 dissolved in ethanol
  –(Role —> Nucleophile).

Question 10

Dehydration for halogenoalkane is what mechanism?

Answer 10

Elimination removal of small molecule (often water).

Question 11

Elimination:
1) Conditions
2) Reagent
3) Role / type

Answer 11

1) Dissolved in ethanol, under heat
2) K/NaOH
3) Base (solvent is alcoholic)

Question 12

Halogenoalkanes are used as?

Answer 12

• refrigerants
• pesticides
  -aerosol propellants