A student put separate small samples of 1-chlorobutane, 1-bromobutane and 1-iodobutane into three different test-tubes. Into each test-tube, $1\ \text{cm}^3$ of ethanol was added, then $1\ \text{cm}^3$ of aqueous silver nitrate, $\text{AgNO}_3$. The test-tubes were then shaken gently, set in a test-tube rack and watched for 30 minutes.
A precipitate appeared in every test-tube, although not simultaneously; the quickest turned opaque after about two minutes and the slowest after around 20 minutes.
(a)[1]
What is the identity of the precipitate when 1-chlorobutane is used?
(b)[1]
What colour is this precipitate?
(c)[1]
Which one of the three halogenoalkanes will give a precipitate in about two minutes?
(d)[2]
Use suitable Data Booklet data to explain why this reaction occurs fastest of the three.
Worked solution & mark scheme
This 5-mark question has a full step-by-step worked solution and mark scheme. One marking point: “$\text{AgCl}$ / silver chloride stated” …