Evaluate fuels, including fossil fuels and biofuels, in terms of their energy output, their suitability for purpose, and the nature of products of combustion. Investigate:

A comparison is made between the complete combustion of octane (\(\text{C}_8\text{H}_{18}\)), a component of petrol, and the complete combustion of ethanol (\(\text{C}_2\text{H}_5\text{OH}\)), a biofuel. Both fuels release energy and produce carbon dioxide and water. Which statement best evaluates these fuels in terms of the nature of their combustion products?

A transport company is evaluating two fuels for its fleet of trucks: biodiesel (derived from vegetable oil) and conventional diesel (a fossil fuel). Both fuels undergo complete combustion in the engine. The biodiesel has an energy density of \(37\) MJ/L, while conventional diesel has an energy density of \(38\) MJ/L. The company prioritizes reducing net carbon dioxide emissions to the atmosphere over the fuel's lifecycle. Which statement best evaluates the suitability of biodiesel compared to conventional diesel for this purpose?