Given the following diagrams at 𝑡=0 min and 𝑡=30 min, b. After four half-life periods for a first-order reaction, what fraction of reactant remains? [Section 14.3]

Video transcript

Hello everyone today. We have the following problem. The components of reaction after zero minutes and 20 minutes are shown below after seven half five periods. What fraction of reacting is still present if the reaction is first order? So in general, after in number of have lives, we have the equation the concentration of a. It's going to equal a sub zero over two to the end. After seven half lives of course we can go ahead and plug that in for our zero. So it's going to be two to the seventh and so that's going to give us a final answer of our a sub oh Sub zero over 128 as our final answer. Overall, I hope this helped and until next time.