Step-by-step explanation:
Burning of alcohol produces different products as it depends on the type and nature of alcohol which is being burnt.
Some alcohols upon burning produce toxic gases or products whereas some alcohols on burning does not produce any toxic substances.
For example, when ethanol is burnt then it reacts with oxygen and results in the formation of water and carbon dioxide.
Thus, we can conclude that the statement burning alcohol for fuel is a very efficient process is a false statement.