For the hypothetical reaction A(g) ⟶ B(g), use the graph shown below to find the average rate of reaction for both A and B at the point in the reaction when the concentrations of A and B are equal.

Question

Answer 1

At the point where [A] = [B], the time would be 100 s and the concentrations would be 0.900 M (assuming I'm reading the values on the graph properly).

Since [B] began at 0 M and reached 0.900 M in 100 s, the average rate of reaction would be...

0.900 M / 100 s = 0.00900 M/s for the formation of B

If you chose to use [A] to find the rate, you start at [A] = 1.700 M and end at 100 s with 0.900 M so rate of decrease = 0.900 - 1.700 / 100 s = -0.800 M/100 s = 0.00800 M / s for the disappearance of A.