Question

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 5.5×10−2 (M⋅s)−1 .


Part A: Write the rate law for the reaction.

A) Rate=k

B) Rate=k[AB]

C) Rate=k[AB]2

D) Rate=k[AB]3


Part B: What is the half-life when the initial concentration is 0.52 M ?

Express your answer using two significant figures.



t1/2 = ?s


Part C: If the initial concentration of AB is 0.230 M , and the reaction mixture initially contains no products, what are the concentrations of A and B after 75 s ?

Express your answers numerically using two significant figures, separated by a comma.

[A],[B] = ?M

Answer 1

Part A. C) Rate=k[AB]²

Part B. t_1/2 = 1 / (kC₀) = 1 / (5.5 × 10⁻² × 0.52) = 35 s

Part C. [A],[B] = 1 / (kt) - C₀ = 0.012 M