4.2.2 - Haloalkanes Flashcards
What is the stem for F?
Fluoro
What is the stem for Cl?
Chloro
What is the stem for Br?
Bromo
What is the stem for I?
Iodo
Why is the carbon-halogen bond polar?
Halogens are much more electronegative than the carbon atom.
What does the carbon-hydrogen bond result in?
The carbon being electron deficient which means it can be attacked by a nucleophile.
What is a nucleophile?
An electron pair donor.
What are haloalkanes hydrolysed to?
Alcohols.
What are common nucleophiles?
Hydroxide ion, water, ammonia, cyanide ion (NC:- )
When water is used in the reaction what is also produced along with the halogen radical?
H+ ions.
What happens to bond enthalpies as you go down the group, and what does that result in?
They decrease therefore they are hydrolysed faster as the weaker carbon-halogen bond is easier to break and so reacts faster.
How can you compare the reactivity of the haloalkanes?
- Add silver nitrate when reacting the haloalkane with water and ethanol, in separate test tubes.
- The test tube containing the iodoalkane will react first producing a yellow precipitate.
- Followed by a cream precipitate from the bromoalkane and then the white precipitate from the chloroalkane.
But isn’t the I-C bond the least polar?
Bond enthalpy is a more important factor in hydrolysis so therefore iodoalkanes react faster.
What are CFCs?
Organic compounds that only contain chlorine, fluorine and carbon.
What are the useful properties of CFCs?
They are very stable, volatile, non-flammable and non-toxic.
