Consider a second-order reaction in which reactant A decomposes according to the
ID: 726953 • Letter: C
Question
Consider a second-order reaction in which reactant A decomposes according to the chemical equation:2A---> products.
The data given below is the time, in minutes, and the corresponding change in the concentration of reactant A for this reaction:
t (min) [A]t(M)
0.00 0.500
20.0 0.382
40.0 0.310
60.0 0.260
80.0 0.224
For a second-order reaction, the rate constant k is the slope of the graph of 1/[A] versus t. Based on this information and the data given, calculate the rate constant k for the reaction.
Express your answer in (M*-1)(min*-1) to three significant figures.
Explanation / Answer
t (min) [A]t(M) [A]t(M-1)
0.00 0.500 2.00
20.0 0.382 2.62
40.0 0.310 3.23
60.0 0.260 3.85
80.0 0.224 4.46
the best fit line for the process(via Excel) is
(1/[A]) = 0.0308t + 2
slope = K = 0.0308 M-1min-1