Final answer:
The average rate of formation of substance B between 0.00 s and 10.0 s is 0.0375 mol L⁻¹ s⁻¹, and the instantaneous rate of formation at 15.0 s is 0.023 mol L⁻¹ s⁻¹.
Step-by-step explanation:
The question asks to determine the average rate of formation of substance B from time t=0 s to t=10 s, and also to find the instantaneous rate of formation at t=15 s. From the provided information, for the time period of 0 - 10 s, the average rate is 0.0375 mol L⁻¹ s⁻¹. The instantaneous rate of formation of B at 15.0 s is given as 0.023 mol L⁻¹ s⁻¹.
To calculate the average rate over a time interval, we use the formula: Average Rate = Δ[Concentration] / ΔTime. Here, the change in concentration (Δ[Concentration]) is not provided, but the average rates for corresponding time intervals are provided. Consequently, we can use the given average rate directly without additional calculations to answer the question. Hence, the average rate of formation of B between 0.00 s and 10.0 s is 0.0375 mol L⁻¹ s⁻¹, and the instantaneous rate of formation of B at 15.0 s is 0.023 mol L⁻¹ s⁻¹.