---
title: "A student studies the decomposition of a hypothetical reactant, \\(\\text{A(aq)} \\rightarrow \\text{products}\\), at constant temperature. The student measures the reactant concentration at several times and plots the data as shown.  Which of the following correctly identifies the order of the reaction with respect to \\(\\text{A}\\) and justifies the answer?"
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url: "https://nerd-notes.com/ubq/119447/"
date_modified: "2026-08-19T12:40:27+00:00"
---

# A student studies the decomposition of a hypothetical reactant, \(\text{A(aq)} \rightarrow \text{products}\), at constant temperature. The student measures the reactant concentration at several times and plots the data as shown.

Which of the following correctly identifies the order of the reaction with respect to \(\text{A}\) and justifies the answer?

A student studies the decomposition of a hypothetical reactant, \(\text{A(aq)} \rightarrow \text{products}\), at constant temperature. The student measures the reactant concentration at several times and plots the data as shown.

Which of the following correctly identifies the order of the reaction with respect to \(\text{A}\) and justifies the answer?

![Draw a grayscale Cartesian graph on a white background. The horizontal axis is labeled “Elapsed time (s)” and extends from 0 to 40, with evenly spaced tick marks at 0, 10, 20, 30, and 40. The vertical axis is labeled “\(1/[\text{A}]\ (\text{M}^{-1})\)” and extends from 0 to 10, with evenly spaced tick marks at 0, 2, 4, 6, 8, and 10. Place five solid black circular data points at the exact coordinates \((0,2)\), \((10,4)\), \((20,6)\), \((30,8)\), and \((40,10)\). Draw a thin solid straight best-fit line through all five points. Use bare axes without gridlines. No legend, equation, title, arrows, or additional annotations appear.](https://nerd-notes.com/wp-content/uploads/ubq-frq-generated/stem-fig-1-1787143227-TAVcj6.jpg)

- **A.** The reaction is zero order because any straight-line plot against elapsed time indicates that the reactant is consumed at a constant rate.
- **B.** The reaction is second order because the integrated second-order rate law predicts a linear relationship between \(1/[\text{A}]\) and elapsed time.
- **C.** The reaction is first order because the integrated first-order rate law predicts a linear relationship between \(1/[\text{A}]\) and elapsed time.
- **D.** The reaction order cannot be determined because neither the initial rate nor the value of the rate constant is provided.

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/119447/*