---
title: "A student investigates the kinetics of the gas-phase reaction represented by the balanced equation below:  \\[2\\text{NO}_2\\text{(g)} + \\text{F}_2\\text{(g)} \\rightarrow 2\\text{NO}_2\\text{F(g)}\\]  A proposed mechanism for the reaction consists of two elementary steps:  \\[\\text{Step 1: } \\text{NO}_2\\text{(g)} + \\text{F}_2\\text{(g)} \\rightarrow \\text{NO}_2\\text{F(g)} + \\text{F(g)} \\quad (\\text{slow})\\] \\[\\text{Step 2: } \\text{NO}_2\\text{(g)} + \\text{F(g)} \\rightarrow \\text{NO}_2\\text{F(g)} \\quad (\\text{fast})\\]  If the initial concentration of \\(\\text{NO}_2\\text{(g)}\\) is doubled while the initial concentration of \\(\\text{F}_2\\text{(g)}\\) and the temperature remain constant, which of the following correctly predicts the effect on the initial rate of the reaction?"
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url: "https://nerd-notes.com/ubq/119688/"
date_modified: "2026-08-21T08:12:03+00:00"
---

# A student investigates the kinetics of the gas-phase reaction represented by the balanced equation below:

\[2\text{NO}_2\text{(g)} + \text{F}_2\text{(g)} \rightarrow 2\text{NO}_2\text{F(g)}\]

A proposed mechanism for the reaction consists of two elementary steps:

\[\text{Step 1: } \text{NO}_2\text{(g)} + \text{F}_2\text{(g)} \rightarrow \text{NO}_2\text{F(g)} + \text{F(g)} \quad (\text{slow})\]
\[\text{Step 2: } \text{NO}_2\text{(g)} + \text{F(g)} \rightarrow \text{NO}_2\text{F(g)} \quad (\text{fast})\]

If the initial concentration of \(\text{NO}_2\text{(g)}\) is doubled while the initial concentration of \(\text{F}_2\text{(g)}\) and the temperature remain constant, which of the following correctly predicts the effect on the initial rate of the reaction?

A student investigates the kinetics of the gas-phase reaction represented by the balanced equation below:

\[2\text{NO}_2\text{(g)} + \text{F}_2\text{(g)} \rightarrow 2\text{NO}_2\text{F(g)}\]

A proposed mechanism for the reaction consists of two elementary steps:

\[\text{Step 1: } \text{NO}_2\text{(g)} + \text{F}_2\text{(g)} \rightarrow \text{NO}_2\text{F(g)} + \text{F(g)} \quad (\text{slow})\]
\[\text{Step 2: } \text{NO}_2\text{(g)} + \text{F(g)} \rightarrow \text{NO}_2\text{F(g)} \quad (\text{fast})\]

If the initial concentration of \(\text{NO}_2\text{(g)}\) is doubled while the initial concentration of \(\text{F}_2\text{(g)}\) and the temperature remain constant, which of the following correctly predicts the effect on the initial rate of the reaction?

- **A.** The initial rate will quadruple because the stoichiometric coefficient of \(\text{NO}_2\text{(g)}\) in the balanced overall chemical equation is \(2\).
- **B.** The initial rate will quadruple because \(\text{NO}_2\text{(g)}\) is a reactant in both elementary steps of the mechanism.
- **C.** The initial rate will double because \(\text{NO}_2\text{(g)}\) is consumed at twice the rate of \(\text{F}_2\text{(g)}\) in the overall reaction.
- **D.** The initial rate will double because the rate-determining step is first order with respect to \(\text{NO}_2\text{(g)}\).

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/119688/*