Quick questions on Halogenoalkanes - WJEC A-Level Chemistry

With hot ethanolic (alcoholic) $\text{KOH}$, a halogenoalkane undergoes elimination instead, losing $\text{HX}$ to form an alkene. The same reagent in aqueous solution favours substitution; in ethanol it favours elimination.

Each nucleophile gives a different and useful product, so substitution is a versatile synthetic tool. Hydroxide gives an alcohol, opening the route to oxidation products. Cyanide gives a nitrile, lengthening the carbon chain by one and providing a group that can be reduced to an amine or hydrolysed to a carboxylic acid. Excess ammonia gives an amine.

The order of $\text{C}-\text{X}$ bond strength can be shown experimentally by warming the three halogenoalkanes with aqueous silver nitrate in ethanol and timing the appearance of the silver halide precipitate. The iodoalkane reacts fastest (cream-yellow $\text{AgI}$ appears first), then the bromoalkane (cream $\text{AgBr}$), then the chloroalkane (white $\text{AgCl}$ slowest). This confirms that the weaker $\text{C}-\text{I}$ bond breaks most readily, the controlling factor being bond strength rather than bond polarity.

Recognising that chlorine radicals from CFCs catalytically destroy ozone led to a worldwide phase-out of CFCs, an example of chemistry informing policy. Nitriles in synthesis. Substitution with cyanide adds a carbon and creates a nitrile that can be reduced to an amine or hydrolysed to a carboxylic acid, a key chain-lengthening step in synthesis.

Name the organic product when 1-bromopropane reacts with aqueous sodium hydroxide. [1 mark]

State the reagent and condition that convert 2-bromobutane into an alkene. [1 mark]

Write the equation for the chlorine radical reacting with ozone. [1 mark]

Name the product when a halogenoalkane reacts with potassium cyanide. [1 mark]

State the order of hydrolysis rate for 1-chloro-, 1-bromo- and 1-iodobutane, fastest first. [1 mark]