Final answer:
The rate of reaction can be calculated by taking the ratio of the change in concentration of the reactant to the time interval. In this case, since there is a 1:1 ratio of disappearance to appearance, you can take the rate of disappearance of the reactant as the rate of appearance of the product.
Step-by-step explanation:
The rate of reaction can be calculated by taking the ratio of the change in concentration of the reactant to the time interval. In this case, since there is a 1:1 ratio of disappearance to appearance, you can take the rate of disappearance of the reactant as the rate of appearance of the product. For example, if the rate of disappearance of A is 0.002 mol/L/s, then the rate of appearance of B would also be 0.002 mol/L/s.