CHEMISTRY · Multi-part · CBSE · Chemistry · Chemical Kinetics · Chemical Kinetics
Problem
A reactant X disappears in solution at 298K. A student proposes that the reaction could be either zero order or first order with respect to X. The following concentration–time data were collected:
Time (min) | 0.0 | 10.0 | 20.0 | 30.0 | 40.0
:--|:--|:--|:--|:--|:--
[X] (M) | 0.400 | 0.300 | 0.200 | 0.100 | 0.0500
(a) Using an appropriate quantitative method, determine whether the reaction is zero order or first order in X. Clearly show the reasoning and calculations that support your conclusion.
(b) For the correct rate law identified in part (a), calculate the numerical value and units of the rate constant k using the data in the table.
(c) Predict the time, in minutes, required for [X] to decrease from 0.400\,M to 0.0100\,M at 298K. Show your calculation.
(d) Suppose a separate trial is started at the same temperature with [X]0=0.800M. Qualitatively discuss how the shape and slope of a concentration–time graph for this trial would compare with the graph for the original data set. Provide reasoning based on your identified rate law.