Question

Consider the balanced chemical equation. H₂O₂(aq) + 3I⁻(aq) + 2H⁺(aq) → I³⁻(aq) + 2H₂O(l) In the first 13.0 s of the reaction, the concentration of I− drops from 1.000 M to 0.842 M .

Predict the rate of change in the concentration of H₂O₂ (Δ[H₂O₂]/Δt). Express the rate to three significant figures and include the appropriate units. Δ[H₂O₂]/Δt Δ[H₂O₂]/Δ t =

Answer 1

The rate of change in H₂O₂ concentration (Δ[H₂O₂]/Δt) given the drop in I⁻ concentration from 1.000 M to 0.842 M over 13.0 s is 0.00405 M/s, calculated using the stoichiometry of the balanced chemical equation.

Step-by-step explanation:

The student asked to predict the rate of change in the concentration of H₂O₂ (H2O2) during a reaction.

First, we observe that the concentration of I⁻ drops from 1.000 M to 0.842 M over 13.0 s.

Since the balanced chemical equation shows that H₂O₂ and I⁻ react in a 1:3 molar ratio, we can calculate the change in H₂O₂ concentration using this stoichiometry.

The change in concentration of I⁻ (Δ[I⁻]) is 1.000 M - 0.842 M = 0.158 M.

Because 3 moles of I⁻ react for every mole of H₂O₂, the change in H₂O₂ concentration (Δ[H₂O₂]) is

0.158 M / 3 = 0.0527 M.

Over a period of 13.0 s, the rate of change in H₂O₂ concentration (Δ[H₂O₂]/Δt) is

0.0527 M / 13.0 s = 0.00405 M/s (to three significant figures).