Halogenoalkanes

EasyMedium
123456789101112131415161718192021222324
Question 24
Medium

This question is about reactions of alkanes and halogenoalkanes.

1.

Alkanes can be used as fuels. Give an equation for the complete combustion of octane (C8H18\text{C}_8\text{H}_{18}C8​H18​) in an excess of oxygen.

[1]
2.

Octane can be obtained from the catalytic cracking of pentadecane (C15H32\text{C}_{15}\text{H}_{32}C15​H32​) at a high temperature.

  • Identify a suitable catalyst for this process.
  • Give one condition other than high temperature.
  • Give an equation for the catalytic cracking of one molecule of pentadecane to produce one molecule of octane, one molecule of cyclopentane, and one other product.
[3]
3.

Alkanes can be used in free-radical substitution reactions to produce halogenoalkanes. Give equations for the propagation steps in the reaction of propane to form 2-bromopropane.

[2]
4.

Chlorofluorocarbons (CFCs) are a group of halogenoalkanes whose use has been restricted due to their environmental impact. The structure of a CFC is shown below:

A Lewis structure representing a chlorofluorocarbon (CFC) molecule. It has a central two-carbon single bond (C-C). The left carbon is bonded to three fluorine atoms (F). The right carbon is bonded to two chlorine atoms (Cl) and one fluorine atom (F).

  • Identify the radical produced from this CFC that is responsible for the depletion of ozone in the atmosphere.
  • Explain, with the aid of equations, why a single radical can cause the decomposition of many molecules of ozone.
[4]

Halogenoalkanes Questions

  1. A Level
  2. /Chemistry
  3. /Halogenoalkanes