Combustion of alkanes and pollutionAQA A-Level Chemistry: Mind map

Exam questions on Combustion of alkanes and pollution

1. A petrol engine burns octane, C₈H₁₈, in a limited supply of air. A mechanic notices that the exhaust gas contains carbon monoxide and black particles.
   Explain why the exhaust gas contains carbon monoxide and carbon when the supply of air is limited.2 marks
2. A modern petrol car has a catalytic converter containing platinum and rhodium on a ceramic honeycomb. The exhaust gases leaving the engine contain nitrogen oxides (NOx), carbon monoxide and unburned hydrocarbons.
   Hexane, C₆H₁₄, is one of the unburned hydrocarbons in the exhaust gases. Write an equation for its complete oxidation in the catalytic converter.2 marks
3. An oil-fired power station burns a fuel oil that contains sulfur impurities. Before the flue gases are released, they are passed through a wet mixture of calcium carbonate in water.
   Explain why sulfur dioxide is formed when the fuel oil is burned, and describe one environmental problem that it causes.3 marks