MISSED THIS? Watch KCV 14.3, IWE 14.1; Read Section 14.3. You can click on the Review link to access the section in your eText. In the first 20.0s of this reaction, the concentration of HBr dropped from 0.550M to 0.452M. Calculate the average rate of the reaction in this time interval. Consider the following reaction: Express your answer in moles per liter per second to two significant figures. 2HBr(g)H2(g)+Br2(g) X Incorrect; Try Again; 3 attempts remaining