A man is working inside an enclosed well with a petrol generator running in order to power a lamp to provide light.

1. aExplain why it is dangerous for the man to work in these conditions. [2]
2. bPetrol is a mixture of hydrocarbons which belong to the alkane homologous series. What is a hydrocarbon? [1]
3. cState two characteristics of a homologous series. [2]

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