1-bromobutane reacts with aqueous sodium hydroxide to form butan-1-ol. In the diagram, the propyl group is shown as C3H7.
(a)
Name the mechanism.
[1 mark]
(b)
Draw the curly arrows for the mechanism.
[2 marks]
(c)
State the conditions for this reaction.
[1 mark]
4 marksCore chemistry3.3.3.1, 3.3.1.1
1-bromopropane is heated under reflux with potassium cyanide in aqueous ethanol.
(a)
Name the organic product.
[1 mark]
(b)
Draw the curly arrows for the mechanism.
[2 marks]
(c)
Give a structural formula of the product.
[1 mark]
4 marksUnfamiliar context3.3.3.1
A student warms equal amounts of 1-chlorobutane, 1-bromobutane and 1-iodobutane separately with aqueous silver nitrate in ethanol and times how long a precipitate takes to appear. The times are 5 s, 95 s and over 600 s, but the labels have been lost.
(a)
Deduce which halogenoalkane gave the precipitate in 5 s.
[1 mark]
(b)
Explain the order of the times.
[2 marks]
(c)
Predict how 1-fluorobutane would behave in the same test, and explain.
[1 mark]
4 marksUnfamiliar context3.3.3.1, 3.3.11.1
2-bromopropane is heated in a sealed tube with an excess of ammonia in ethanol.
(a)
Draw the curly arrows for the first step, in which ammonia attacks 2-bromopropane.
[2 marks]
(b)
Name the amine formed.
[1 mark]
(c)
Explain why an excess of ammonia is used.
[1 mark]
2 marksCore chemistry3.3.3.1
Halogenoalkanes differ in how fast they react with nucleophiles.
(a)
Which compound reacts fastest with aqueous hydroxide ions?
[1 mark]
(b)
Explain why the carbon bonded to the halogen is attacked by nucleophiles.
[1 mark]
4 marksUnfamiliar context3.3.3.1, 3.1.2.5
A chemist converts 1-bromobutane into pentanenitrile using KCN. She starts with 6.85 g of 1-bromobutane (Mr = 137.0) and obtains 2.91 g of pentanenitrile (Mr = 83.0).