Are all biofuels a mixture, hence use #kJg^-1#and fossil fuels a pure substance?

1 Answer
Feb 19, 2018

Rather the reverse in fact...

Explanation:

Ethanol is the most commonly produced biofuel....i.e. ethanol derived from fermentation...and this is to a first approx. a pure substance. On the other hand, fossil fuels are a mixture of several compounds, i.e. #"petroleum spirit"#, or #"petroleum ethers"#. The juice that we put in a petrol engine is the isomeric butanes, pentanes, hexanes, and octanes....i.e. several formulae, and different isomeric mixes.