Skip to main content
Ch.14 - Chemical Kinetics
Chapter 14, Problem 82

Nitrosyl bromide decomposes at 10 °C. NOBr1g2S NO1g2 + 1>2 Br21g2 Use the following kinetic data to determine the order of the reaction and the value of the rate constant for consumption of NOBr.Chemical reaction diagram showing the decomposition of nitrosyl bromide at 10 °C.

Verified step by step guidance
1
Step 1: Write down the balanced chemical equation for the decomposition of nitrosyl bromide: 2 NOBr(g) → 2 NO(g) + Br2(g).
Step 2: Analyze the provided kinetic data to determine the reaction order. This typically involves plotting concentration vs. time data and determining which plot (zero-order, first-order, or second-order) gives a straight line.
Step 3: For a zero-order reaction, plot [NOBr] vs. time. For a first-order reaction, plot ln[NOBr] vs. time. For a second-order reaction, plot 1/[NOBr] vs. time.
Step 4: Determine the reaction order by identifying which plot results in a straight line. The slope of this line will be related to the rate constant.
Step 5: Calculate the rate constant (k) using the slope of the straight line from the appropriate plot. For a first-order reaction, the slope of the ln[NOBr] vs. time plot is -k. For a second-order reaction, the slope of the 1/[NOBr] vs. time plot is k.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
7m
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Reaction Order

The order of a reaction refers to the power to which the concentration of a reactant is raised in the rate law. It indicates how the rate of reaction depends on the concentration of reactants. For example, a first-order reaction depends linearly on the concentration of one reactant, while a second-order reaction depends on the square of the concentration. Determining the order is crucial for understanding the kinetics of the reaction.
Recommended video:
Guided course
00:36
Average Bond Order

Rate Constant (k)

The rate constant, denoted as 'k', is a proportionality factor in the rate law that relates the rate of a reaction to the concentrations of the reactants. It is specific to a given reaction at a particular temperature and is influenced by factors such as temperature and the presence of catalysts. The value of 'k' can be determined experimentally and is essential for calculating the rate of reaction.
Recommended video:
Guided course
01:14
Equilibrium Constant K

Kinetic Data Analysis

Kinetic data analysis involves examining experimental data to determine the relationship between reactant concentrations and reaction rates. This analysis often includes plotting concentration versus time to derive rate laws and reaction orders. By analyzing the data, one can identify the type of reaction and calculate the rate constant, which is vital for predicting how the reaction will proceed under various conditions.
Recommended video:
Guided course
06:11
Dimensional Analysis