The decomposition of substance A was monitored at 60 °C. The concentration of A was measured every 3.0 min, yielding the data in the table. Each concentration measurement has an uncertainty of ±0.005 M.
Time (min)
[A] (M)
0.0
0.500
3.0
0.391
6.0
0.306
9.0
0.237
12.0
0.185
15.0
0.144
No other reactants or products interfere with the measurement of A.
(a) Transform the data in a single, clearly labeled graph so that the plotted points form a straight line suitable for linear regression. State the variables you plotted and justify this choice based on the appearance of the resulting graph.
(b) Using an appropriate best-fit line for the transformed data, determine the numerical value and units of the rate constant k. Include the equation of the best-fit line in your response.
(c) Using the rate constant obtained in part (b), calculate the predicted concentration of A after 25 min.
(d) Discuss how the stated measurement uncertainty (±0.005 M) influences the reliability of the value of k determined in part (b) and the prediction made in part (c).