Question

Without knowing anything about the specific chemical reaction, which of the statements below is the best indicator that the reaction involved a redox reaction?

a. The color of the reactants changed.
b. Heat was released during the reaction.
c. There was a change in the oxidation states of the elements.
d. The reaction produced a gas.

Answer 1

The clearest indicator of a redox reaction is a change in the oxidation states of the elements involved, as this signifies the transfer of electrons.

Step-by-step explanation:

The best indicator that a chemical reaction involved a redox reaction is option c. There was a change in the oxidation states of the elements. Redox reactions are characterized by the transfer of electrons, which causes a change in the oxidation numbers of atoms.

When the oxidation number of an atom in a substance increases, we say the atom has been oxidized, and when it decreases, the atom is reduced. This is a definitive indication of a redox reaction occurring.