ATI TEAS (Test of Essential Academic Skills) Version 7ScienceMedium

A chemist is attempting to synthesize a new compound. They notice that the reaction proceeds much faster when a small amount of a specific substance is added, but this substance is not consumed in the overall reaction. What role is this substance playing?

  1. AReactant
  2. BInhibitor
  3. CProduct
  4. DCatalyst
Show answer & explanation

Correct answer: D. Catalyst

A catalyst is a substance that increases the rate of a chemical reaction without being consumed in the reaction itself. It provides an alternative reaction pathway with a lower activation energy.

Why the other options are wrong

  • A. A reactant is a substance consumed in a chemical reaction.
  • B. An inhibitor slows down or stops a chemical reaction.
  • C. A product is a substance formed as a result of a chemical reaction.

Catalyst

A substance that increases the rate of a chemical reaction without undergoing any permanent chemical change itself.

  • Lowers activation energy.
  • Not consumed in the reaction.
  • Can be recovered unchanged after the reaction.

Memory trick: A catalyst 'cuts' the time of reaction.

More Science questions