Topic 10

Question 1

What colour precipitate will form.

Answer 1

chloroethane + silver nitrate = white precipitate AgCl
bromoethane + silver nitrate = cream precipitate AgBr
iodoethane + silver nitrate = yellow precipitate AgI

Question 1

How can halogenoalkane be identified

Answer 1

Add ethanol and aqueous silver nitrate solution to the halogenoalkane. If a halogenoalkane is present, then a silver halide precipitate will form.

Question 2

how can chloroalkanes be form alcohol

Answer 2

add PCI5

Question 3

test for alcohols

Answer 3

soltion must be neutral, then add PCI5 to the liquid/ solution, if a violent reaction occurs and hydrogen chloride gas is released then alcohol is present.

Question 4

How can bromoalkanes be formed from alcohol

Answer 4

add potassium bromide and concentrated sulfuric acid, which then produces hydrogen bromide that will react with the alcohol.

Question 5

how do iodoalkanes be formed from alcohols.

Answer 5

add red phosphorus and iodine

Question 6

alcohol to alkene

Answer 6

elimination
concentrated phosphoric acid

Question 7

oxidation

Answer 7

use to oxidise = acidified potassium dichromate
color change organe to green