Question

Kinetic data for a reaction, A → B, was measured and the same data were plotted in three different ways. The results of the plots are below.

Plot 1:
A plot of [A] versus time had a line of best fit as y = –0.0505 x + 0.275 R2 = 0.98493.
Plot 2:
A plot of ln [A] versus time had a line of best fit as y = –0.0026 x – 1.290 R2 = 0.99997.
Plot 3:
A plot of $$
versus time had a line of best fit as y = 0.00001 x + 3.636 R2 = 0.98653.
a. Plot 1 represents zero-order reaction
b. Plot 2 represents first-order reaction
c. Plot 3 represents second-order reaction
d. Plot 2 represents zero-order reaction

Answer 1

Plot 1 showing linear concentration versus time indicates zero-order kinetics; statement a is correct. Plot 2 showing a linear ln[A] versus time represents first-order kinetics; statement b is correct. While Plot 3 is indicated as a second-order reaction, the full equation form is missing due to a typo, but based on context, we treat statement c as accurate.

Step-by-step explanation:

When analyzing kinetic data, the reaction order can be determined by the way the data fits into different types of plots. The reaction order indicates how the rate of the reaction depends on the concentration of the reactants.

In a zero-order reaction, a plot of the concentration of the reactant, [A], versus time, t, yields a straight line with a slope of –k. According to the data provided, Plot 1 follows this trend with a linear equation – therefore, statement a is correct, Plot 1 represents a zero-order reaction.

For a first-order reaction, a plot of the natural logarithm of the reactant concentration, ln[A], versus time will be linear with a slope of –k. Given that Plot 2 has a linear fit with an equation in this form, it suggests that the reaction follows first-order kinetics – thus, statement b is correct, Plot 2 represents a first-order reaction.

A second-order reaction can be illustrated by a linear plot of 1/[A] (inverse concentration) versus time, where the slope would be k. Given this information, statement c is correct, and Plot 3 would represent a second-order reaction if it had this form. However, because there is a typo where the plot form for the second order isn't mentioned, assume this statement is accurate based on provided context.