Question

Consider the decomposition reaction: AB(g)-->A(g)+B(g). The rate law for the reaction is: rate=k[AB]^2, where k=0.00846 M^-1 min^-1. After 5.25 hours, what is the percent of AB that decomposed if the initial concentration is 2.00 M?

Answer 1

https://chem.libretexts.org/Textbook_Maps/Physical_and_Theoretical_Chemistry_Textbook_Maps/Supplemental_Modules_(Physical_and_Theoretical_Chemistry)/Kinetics/Reaction_Rates/Second-Order_Reactions

So if the half-life is given by Thalf=1/(k(AB))=1/.0169=59.2 min=5.32 halflives

and 5.25 hours =5.25*60min=315min=315/59.2 halflives=5.32 halflives

amount remaining/original =(1/2)^5.32=.0250
percent remain = above x 100