Consider the balanced chemical equation. H2O2(aq)+3I−(aq)+2H+(aq)→I3−(aq)+2H 2O(l) In the first 15.0 s of the reaction, the concentration of I− drops from 1.000 M to 0.871 M .Part A 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 [ H 2 O 2 ] / Δ t =

Part B Predict the rate of change in the concentration of I3− (Δ[I3−]/Δt). Express the rate to three significant figures and include the appropriate units. Δ[I3−]/Δt Δ [ I 3 − ] / Δ t =

Part A. 8.60 × 10⁻³ M/s

Part B. 8.60 × 10⁻³ M/s

Explanation:

Let's consider the following balanced chemical equation.

H₂O₂(aq) + 3 I⁻(aq) + 2 H⁺(aq) → I₃⁻(aq) + 2 H₂O(l)

Part A

The rate of change in the concentration of H₂O₂ is:

-Δ[H₂O₂]/Δt = -(0.871 M - 1.000 M)/15.0 s = 8.60 × 10⁻³ M/s

Part B

The molar ratio of H₂O₂(aq) to I₃⁻(aq) is 1:1. The rate of change in the concentration of I₃⁻ is:

8.60 × 10⁻³ mol H₂O₂/L.s × (1 mol I₃⁻/1 mol H₂O₂) = 8.60 × 10⁻³ mol I₃⁻/L.s = 8.60 × 10⁻³ M/s

answer: c. the experiment shows that the red substance experienced a chemical change.

explanation: chemical change is the change in which chemical composition of the substance changes. physical change is the change in which there is no change in chemical composition.

chemical changes are accompanied by following changes:

a) precipitate formation

b) energy is released or absorbed

c) formation of bubbles

d) change in color

as it is given that the red color has disappeared and there is production of gas, it means the red substance has undergone a chemical change.

e

1. they vary with a higher number because boiling is way hotter than melting