Although expensive, platinum is used as a catalyst to break down harmful gases in car exhaust into less harmful gases. Which statement best describes platinum in this use?

Platinum in a car’s catalytic converter is a solid that acts on gases, so the catalyst and reactants are in different phases. That makes it a heterogeneous catalyst. It is not consumed by the reaction, so only a small amount is needed, and it remains on the converter rather than mixing with the gaseous products, making it easy to separate.

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