Organic Chemistry: Haloalkanes Flashcards
1
Q
Haloalkanes
A
Organic compounds with a halogen somewhere on the chain
2
Q
Haloalkane General Formula
A
CnH2n+1X (X is a halogen)
3
Q
Naming Haloalkanes
A
- Halogen is added on as a prefix with an -ane added on the end
- E.g. Bromopropane
4
Q
Primary Haloalkane
A
There is only 1 carbon attached to the carbon with the halogen
5
Q
Secondary Haloalkane
A
There are 2 carbons attached to the carbon with halogen
6
Q
Tertiary Haloalkane
A
- There are 3 carbons attached to the carbon with the halogen
- Will most likely contain a methyl group as the 3rd carbon
7
Q
Bonding in Haloalkanes
A
- All have C-X bonds
- The C-X bond is polar (halogen is more electronegative than carbon)
- As you go down group 7 the bond with carbon gets weaker (electronegativity decreases)
8
Q
Are Haloalkanes soluble in water?
A
- No
- The polar C-X bonds aren’t polar enough to make haloalkanes soluble in water
9
Q
Trend in Boiling Point for Haloalkanes
A
- It depends on the number of carbons and hydrogens
- Increases down group 7
- Increases with chain length
10
Q
What do Haloalkanes react with?
A
Nucleophiles
11
Q
Nucleophile
A
- A reagent that donates a lone pair of electrons to form a new covalent bond
- Examples:
Cyanide (lone pair on the carbon)
Hydroxide ions (lone pair on the oxygen)
Ammonia (lone pair on the nitrogen)
12
Q
How does bond strength change down group 7?
A
- C-X bonds get weaker
- Fluorine is the smallest atom so it forms the strongest bonds
- Iodo- is the weakest and fluoro- is the strongest
13
Q
What do curly arrows show?
A
The movement of a pair of electrons
14
Q
Nucleophilic Substitution
A
When a nucleophile is added to a haloalkane and the functional groups swap as a result
15
Q
Nucleophilic Substitution of OH- Ions
A
- Reagent is NaOH or KOH
- Cold
- In aqueous solution (can’t be alcoholic or elimination would happen instead)
- Alcohol and Sodium/Potassium Halide is formed
