Question

In a catalytic converter, the unburnt hydrocarbons in the fuel are converted to ______________.

• A. carbon
• B. carbon monoxide
• C. carbon dioxide and water vapour
• D. carbon monoxide and water vapour

Answer 1

The correct option is C carbon dioxide and water vapour

Catalytic converters convert toxic gases and pollutants present in the exhausts, emitted by internal combustion engines, into less-toxic pollutants. These use expensive metals such as platinum, palladium and rhodium as they are inert metals and have high resistance to oxidation, even at high temperatures.

These metals are used for catalyzing redox reactions that convert toxic compounds into non-toxic ones. Redox reaction is a reaction in which one reactant undergoes oxidation whereas the other gets reduced during the course of reaction.

Figure : Catalytic converter

As the exhaust from automobiles passes through the catalytic converter, unburnt hydrocarbons get converted into carbon dioxide and water, carbon monoxide gets converted to carbon dioxide and nitric oxide gets changed to nitrogen gas. Hence option c is correct.

Figure : Reactions in catalytic converter

To avoid inactivation of the catalyst by lead, vehicles that are equipped with catalytic converters have to use unleaded petrol.