Food waste can be decomposed anaerobically in an industrial compost digester to produce a useful biogas mixture.
The pie chart below shows the percentage composition of gases in a sample of biogas collected from the digester.
a.[1]
Gas X is the main combustible fuel gas in the biogas. What is the chemical name of Gas X?
b.[2]
Calculate the percentage of Gas X in the biogas sample. Show your working.
c.[2]
Name two groups of microorganisms that are responsible for the decomposition of organic waste.
d.[2]
Explain how a temperature increase from 15 ∘C15\text{ }^\circ\text{C}15 ∘C to 38 ∘C38\text{ }^\circ\text{C}38 ∘C affects the rate of decay by these microorganisms.