Question

what is the role of potassium iodide (ki) in the decomposition of hydrogen peroxide (h₂o₂)?
select one:
○ it is the solvent for the hydrogen peroxide.
○ it is a catalyst that speeds up the rate of the decomposition reaction.
○ it is a reactant that gets consumed in the reaction.
○ it is an indicator that changes color when the reaction is complete.

Explanation:

Potassium iodide (\(KI\)) is not consumed in the decomposition of hydrogen peroxide (\(H_2O_2\)). It lowers the activation energy of the decomposition reaction \(2H_2O_2
ightarrow 2H_2O + O_2\) without being used up. A solvent would just dissolve \(H_2O_2\) (water is the common solvent for \(H_2O_2\) in such reactions). A reactant would be consumed, and an indicator's role is to show reaction progress via color - change (not relevant here as \(KI\) doesn't act this way).

Answer:

It is a catalyst that speeds up the rate of the decomposition reaction.