Core Practical 4

Question 1

What trend do your results in part 1 show? Explain the trend.

Answer 1

1-iodobutane is the fastest, then 1-bromobutane, the slowest is 1-chorobutane. Iodoalkanes react fastest because the C-I bond enthalpy is the weakest and therefore easiest to break.

Question 2

What trend do your results in part 2 show? Explain the trend.

Answer 2

Tertiary haloalkanes reacted faster as they undergo SN1. Primary haloalkanes react the slowest as they undergo SN2.

Question 3

Write an equation for the reaction of 1-bromobutane with water.

Answer 3

CH3CH2CH2CH2Br + H2O -> CH3CH2CH2CH2OH + :Br- + H+

Question 4

In these reaction a precipitate forms. Identify the precipitate formed when the halogenoalkane is 1-iodobutane.

Answer 4

Silver iodide
Ag+ (aq) + I- (aq) -> AgI (s)

Question 5

Explain why ethanol is used in these reactions.

Answer 5

Because the haloalkanes are dissolved in ethanol.

Question 6

Explain why water is able to act as a nucleophile.

Answer 6

It has two lone pairs of electrons

Question 7

Explain why water is used as the nucleophile rather than hydroxide ions?

Answer 7

Due to its stability, low reactivity level, and abundance.