The oxidation of iodide ion by hydrogen peroxide in an acidic solution is described by the balanced equation
The rate of formation of the red triiodide ion, Δ[I3+]/Δt, can be determined by measuring the rate of appearance of the color (Figure 12.5).
Figure 12.5
A sequence of photographs showing the progress of the reaction of hydrogen peroxide (H2O2) and iodide ion (I−). As time passes (left to right), the red color due to the triiodide ion (I3−) increases in intensity.
Initial rate data at 25 °C and a constant H+ ion concentration are as follows:
- (a) What is the rate law for the formation of I3−?
- (b) What is the value of the rate constant?
- (c) What is the initial rate of formation of I3− when the initial concentrations are [H2O2] = 0.300 M and [I−] = 0.400 M?
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General Chemistry: Atoms First
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