22. Which of the following contains high content of lead? A.Coal B.Cooking gas C.High octane fuel D.Low octane fuel
Answer: Option C Solution: A high-octane-rated fuel, such gasoline contains lead. Straight-run gasoline is distilled directly from crude oil. Once the leading source of fuel, its low octane rating required lead additives. Most countries have phased out leaded fuel. Different additives have replaced the lead compounds. The most popular additives include aromatic hydrocarbons, ethers and alcohol (usually ethanol or methanol). Lead used to be added to petrol and this was the source of high levels of lead in the air.