Which statement best describes the use of catalytic converters in automobiles? They decrease the rate of the reactions that produce harmful gases.
They oxidize hydrocarbons to form less toxic gases.
They combine the larger hydrocarbon molecules with smaller ones.
They increase reaction temperature for cleaner burning.

The statement that best describes the use of catalytic converters in automobiles is;

They oxidize hydrocarbons to form less toxic gases

Explanation:

Catalytic converters

A working engine produces some air pollutants which are made due to fuel not completely burnt in the engine, including unburnt gasoline (a hydrocarbon), nitrogen oxides, and carbon monoxide

Carbon monoxide is poisonous to breathe in if present in the air around us, and nitrogen oxides causes acid rain and smog, while hydrocarbon from the gasoline causes smog

The catalyst in the catalytic converters aids in the conversion of the harmful gases produced by the car engine into harmless gases such as the types of gases already existing in the atmosphere and therefore, can be released into the air

The catalysts in the catalytic converter work by either oxidizing some of the harmful gases such as the unburnt hydrocarbons, or by reducing the other harmful gases such as the nitrogen oxides.

Therefore, the statement that best describes the use of catalytic converters in automobiles is that they oxidize hydrocarbons to form less toxic gases