Question

How do automobiles fitted with catalytic converters reduce air pollution? Suggest the best fuel for such vehicles.

Answer 1

Hint: By using chemical reactions, catalytic converters turn toxic substances in a car's exhaust gases including carbon monoxide, nitric oxide, nitrogen dioxide, and hydrocarbons into less dangerous molecules like carbon dioxide and water vapour.

Complete answer:
Pollutant gases are made up of dangerous molecules, but those molecules are made up of atoms that are rather safe. So, if we could figure out a technique to divide up molecules after they leave a car's engine and before they're pushed into the air, we'd be able to solve the pollution problem—at least in part. A catalytic converter performs this function.
These devices are really less complicated than they appear. A catalyst is a substance that speeds up a chemical reaction without changing itself in the process. It's similar to a sports coach standing by the side of the track yelling at the runners to speed up. The coach does not run; instead, he stands there, waves his arms around, and instructs the runners to speed up. The catalyst's role in a catalytic converter is to speed up the elimination of pollution.Platinum or a platinum-like metal such as palladium or rhodium is used as the catalyst.
A catalytic converter is a big metal box having two pipes that is bolted to the under area of a car. One of them (the converter's "input") is attached to the engine and draws hot, dirty exhaust gases from the cylinders (where the fuel burns and produces power). Which goes out from the output region. Chemical reactions take place on the catalyst's surface as the gases from the engine fumes pass over it, breaking up the polluting gases and transforming them into other gases that can be safely released into the air.

Note:
Expensive metals such as platinum–palladium and rhodium are used as catalysts in catalytic converters. Unburned hydrocarbons are transformed to carbon dioxide and water as the exhaust goes through the catalytic converter. Carbon monoxide and nitric oxide are respectively converted to carbon dioxide and nitrogen gas. The optimum fuel is unleaded gasoline.