Compare and contrast the mechanisms by which 1-chlorobutane, CH₃CH₂CH₂CH₂Cl, and 2-chloro-2-methylpropane, (CH₃)₃CCl, react with aqueous sodium hydroxide, giving two similarities and one difference.

Outline why the rate of reaction of the similar bromo-compounds is faster.

State the organic product of the reaction between 1-chlorobutane, CH₃CH₂CH₂CH₂Cl, and aqueous sodium hydroxide.

Suggest how this product could be synthesized in one step from butanoic acid.

Deduce the name of the class of compound formed when the product of (c)(i) reacts with butanoic acid.

Any two similarities:

heterolytic bond breaking

OR

chloride ions leave

nucleophilic/OH^– substitution

both first order with regard to [halogenoalkane]

One difference:

CH₃CH₂CH₂CH₂Cl is second order/bimolecular/S_N2 AND (CH₃)₃CCl is first order/unimolecular/S_N1

OR

CH₃CH₂CH₂CH₂Cl rate depends on [OH^–] AND (CH₃)₃CCl does not

OR

CH₃CH₂CH₂CH₂Cl is one step AND (CH₃)₃CCl is two steps

OR

(CH₃)₃CCl involves an intermediate AND CH₃CH₂CH₂CH₂Cl does not

OR

CH₃CH₂CH₂CH₂Cl has inversion of configuration AND (CH₃)₃CCl has c. 50 : 50 retention and inversion

Do not accept “produces alcohol” or “produces NaCl”.

Accept “substitution in 1-chlorobutane and «some» elimination in 2-chloro-2-methylpropane”.

[3 marks]

C–Br bond weaker than C–Cl bond

Accept “Br^– is a better leaving group”.

Do not accept "bromine is more reactive".

Do not accept “C–Br bond is longer than C–Cl” alone.

[1 mark]

butan-1-ol/CH₃CH₂CH₂CH₂OH

Do not accept “butanol” for “butan-1-ol”.

Accept “1-butanol”.

Do not penalize for name if correct formula is drawn.

[1 mark]

«reduction with» lithium aluminium hydride/LiAlH₄

Do not accept “sodium borohydride/NaBH₄”.

[1 mark]

ester

[1 mark]