Organic Chemistry: Haloalkanes Flashcards
what is the reaction of haloalkanes?
nucleophilic substitution
what types of haloalkanes can undergo nucleophilic substitutions?
primary haloalkanes
what is a nucleophile?
an electron pair donor to form a new covalent bond
what is the rate of hydrolysis trend of haloalkanes?
increases because the carbon-halogen bond enthalpies decreases as you go down group 7
what is the method of hydrolysis of haloalkanes?
- set up 3 test tubes and in each test tube add 1cm3 of ethanol and 2 drops of either 1-chloro/bromo/iodobutanes
- stand these test tubes in a 60 water bath
- add a test tube containing silver nitrate solution to the water bath and allow all test tubes to reach a constant temperature
- add 1cm3 of silver nitrate to each test tube
- start stopclock and measure the time taken for a precipitate to form
what type of reactions do haloalkanes undergo?
- substitution reaction
- nucleophilic substitution
why does the rate of hydrolysis decrease down the halogens?
- 1-chlorobutane reacts slowest = C-Cl bond is the strongest
- 1-iodobutane reacts fastest = C-I bond is weakest
what does the rate of hydrolysis depend on?
- strength of the carbon-halogen bond
what are the two ways to hydrolyse haloalkanes in substitution reeactions?
- by aqueous alkali
- by water in the presence of AgNO3 and ethanol
what is the aqueous alkali being used to hydrolyse the haloalkanes?
- NaOH(aq)
explain the interaction between water and haloalkanes.
haloalkanes are insoluble in water
where is the water from in the reaction between haloalkanes, ethanol and silver nitrate?
in the aqueous silver nitrate
what is used to combat the insolubility of haloalkanes?
- ethanol solvent
- ethanol allows the water and haloalkane to mix to produce a single solution
