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The following reaction was monitored as a function of time: AB→A+B A plot of 1/[AB] versus time yields a straight line with slope 5.9×10^−2 (M⋅s)^−1.

-What is the value of the rate constant (k) for this reaction at this temperature?
-Write the rate law for the reaction.
-What is the half-life when the initial concentration is 0.51 M?
-If the initial concentration of AB is 0.220 M, and the reaction mixture initially contains no products, what are the concentrations of A and B after 80 s?

User Juhyun
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Final answer:

The rate constant (k) for the reaction is 5.9×10^-2 (M·s)^-1. The rate law of the reaction is rate = k[AB]. The half-life of the reaction is 11.7 seconds when the initial concentration is 0.51 M. After 80 seconds, the concentrations of A and B would be 0.019 M each.

Step-by-step explanation:

The rate constant (k) for the reaction can be determined from the slope of the graph of 1/[AB] versus time. In this case, the slope is given as 5.9×10^-2 (M·s)^-1. Therefore, the value of the rate constant (k) is 5.9×10^-2 (M·s)^-1.

The rate law for the reaction can be determined based on the stoichiometry of the reaction. Since AB is converted into A and B, the rate law can be written as rate = k[AB].

The half-life (t1/2) of a reaction can be calculated using the equation t1/2 = 0.693/k, where k is the rate constant. Substituting the given initial concentration of 0.51 M into the equation gives t1/2 = 0.693/5.9×10^-2 (M·s)^-1 = 11.7 s.

If the initial concentration of AB is 0.220 M and the reaction mixture initially contains no products, the concentrations of A and B after 80 seconds can be calculated using the rate law. Assuming the reaction is first-order with respect to AB, the concentration of AB after 80 seconds is [AB] = [AB]0*e^(-kt), where [AB]0 is the initial concentration and t is the time.

Substituting the given values into the equation, the concentration of AB after 80 seconds is 0.220*e^(-5.9×10^-2*(80)) = 0.038 M. Since AB is converted into equal amounts of A and B, the concentrations of A and B after 80 seconds would be 0.038/2 M.

User Mancestr
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