Large ships burn heavy fuel oil in their engines.
The exhaust gases contain sulfur dioxide, oxides of nitrogen and carbon monoxide.
Heavy fuel oil contains sulfur as an impurity.
Write the balanced symbol equation for sulfur burning in oxygen to make sulfur dioxide.
In the hot engine, nitrogen reacts with oxygen to make nitrogen monoxide, NO.
Write the balanced symbol equation for this reaction.
Carbon monoxide forms when fuels burn in too little oxygen. For example, octane, C8H18\mathrm{C_{8}H_{18}}C8H18, can burn to make carbon monoxide and water only.
Write the balanced symbol equation for this reaction.
Explain why the sulfur dioxide and oxides of nitrogen released by ships are a problem.
Since 2020, ships must use fuel that contains no more than 0.50% sulfur by mass.
Calculate the maximum mass of sulfur in 1000 kg of this fuel.
When the sulfur in this fuel burns, about 10 kg of sulfur dioxide is made.
Explain why the mass of sulfur dioxide made is about twice the mass of sulfur that burns.
Relative atomic masses (Ar): O = 16.0 S = 32.1
51 exam-style questions on OCR GCSE Chemistry 6.3 Interpreting and interacting with earth systems, covering 6.3.1 Formation and evolution of the atmosphere, 6.3.2 The greenhouse effect and climate change, 6.3.3 Sources and problems of atmospheric pollutants, and 6.3.4 Producing potable water. Each one has a worked solution and a mark scheme showing where the marks go.