Haloalkanes

Question 1

How do you identify primary, secondary and tertiary haloalkanes?

Answer 1

1. Locate the halogen
2. Trace it back to the carbon it’s connected to
3. Count how many carbons that carbon is connected to
4. Determine if its primary, secondary or tertiary

Question 2

What are the notations for primary, secondary and tertiary haloalkanes?

Answer 2

Primary = 1°
Secondary = 2°
Tertiary = 3°

Question 3

Describe substitution reactions

Answer 3

• Always reacts with OH (can be NaOH or KOH)
• The OH can be over the arrow or added directly
• Should always produce an alcohol

Question 4

Describe reactions with amines

Answer 4

The haloalkane is heated with a solution of ammonia in ethanol, which has to be done in a sealed tube so the amines don’t disappear into the atmosphere and there’s enough left in the tube

Note: when using NH3, it will form NH2 at the end of the product, as one hydrogen will break off and form a hydrogen halide as another product

Question 5

Describe elimination reactions

Answer 5

An alcoholic NaOH or KOH needs to be heated for the reaction to occur

When the reaction occurs, locate and remove the halogen. Then trace it back to the carbon it was connected to. Remove one hydrogen from an adjacent carbon and insert a double bond.

A primary haloalkane will produce one product. A secondary/tertiary haloalkane will produce two products.

Question 6

What is the order to follow when naming haloalkanes?

Answer 6

Locations of halogens → prefix for the number of halogens → name of the halogens → prefix for the number of carbons → -ane