Decomposition Question

Question

At 40 Celsius, H2O2 (aq) will decompose according to the following reaction:

2H2O2 (aq)→2H2O (l) + O2 (g)

The following data were collected for the concentration of H2O2 at various times.

Time(s) [H2O2](mol/L)

0 1.000

2.16 × 104 0.500

4.32 × 104 0.250

a.) Calculate the average rate of decomposition of H2O2 between 0 and 2.16 × 104 s.

b.) Use the rate to calculate the average rate of production of oxygen gas over the same time period.

Answer 1

a). ∆ [H₂O₂]/t = 0.500 M/2.16x10⁴ s = 2.31x10^-5 M/s

b). ∆ [O₂]/t = 1/2 ∆ [H₂O₂]/t = 1/2 * 2.3x10^-5 M/s = 1.16x10^-5 M/s