Exhibit 13-1 This Graph Shows the Concentration Vs

Exhibit 13-1 This graph shows the concentration vs. time data needed for the following question(s) .
-Refer to Exhibit 13-1. What is the average rate at which concentration decreases, measured between 10 and 30 seconds?

A) 530 mol/L × s
B) 1.9×10 ^{- 3} mol/L × s
C) - 1.9×10 ^{- 4} mol/L × s
D) - 530 mol/L × s
E) cannot answer from the data given