Final answer:
The rate of formation of water (H2O) at the same instant is 5.0 M/s, as it matches the rate of decomposition of hydrogen peroxide (H2O2) due to their stoichiometric relationship in the chemical equation.
Step-by-step explanation:
The reaction 2 H2O2 → 2 H2O + O2 has been given a rate of 5.0 M/s for the decomposition of hydrogen peroxide (H2O2) at a specific time of 10 seconds and at a temperature of 25°C. According to the stoichiometry of the balanced equation, the formation of water (H2O) is directly related to the decomposition of hydrogen peroxide. Since both the reactant and product have a stoichiometric coefficient of 2, the rate of formation of water will be the same as the rate of decomposition of hydrogen peroxide. Therefore, the rate of formation of water (H2O) at the same instant is also 5.0 M/s.