Answer:
The average rate of the reaction is 1.2 × 10⁻³ M/s
Explanation:
The rate of the reaction can be written in terms of the disappearance of reactant A. The average rate of the reaction is given by the variation of the concentration of reactant A over time divided by its stoichiometric coefficient:
average rate of reaction = - 1/2 * (final concentration - initial concentration)/time
Between 0 and 20 s, the average rate of the reaction is:
rate = - 1/2 ( 0.0720 M - 0.1200 M) / 20 s = 1.2 × 10⁻³ M/s