Textbook Question
Consider the reaction: H2(g) + Br2(g) → 2 HBr(g) The graph shows the concentration of Br2 as a function of time. a. Use the graph to calculate each quantity: (iii) the instantaneous rate of formation of HBr at 50 s
Ch.14 - Chemical Kinetics
Chapter 14, Problem 34
Consider the reaction: 2 H2O2(aq) → 2 H2O(l) + O2(g). The graph shows the concentration of H2O2 as a function of time. Use the graph to calculate each quantity: a. the average rate of the reaction between 10 and 20 seconds, b. the instantaneous rate of the reaction at 30 seconds.
Verified step by step guidance1
insert step 1: Identify the relevant data from the graph for the time intervals specified. For part (a), note the concentration of H2O2 at 10 seconds and at 20 seconds. For part (b), note the concentration of H2O2 at 30 seconds.
insert step 2: For part (a), calculate the change in concentration of H2O2 over the time interval from 10 to 20 seconds. This is done by subtracting the concentration at 20 seconds from the concentration at 10 seconds.
insert step 3: For part (a), calculate the average rate of the reaction by dividing the change in concentration by the change in time (20 seconds - 10 seconds). The average rate is given by the formula: \( \text{Average rate} = -\frac{\Delta [\text{H}_2\text{O}_2]}{\Delta t} \).
insert step 4: For part (b), to find the instantaneous rate at 30 seconds, determine the slope of the tangent to the curve at 30 seconds. This can be done by drawing a tangent line at 30 seconds and calculating its slope, which is \( -\frac{d[\text{H}_2\text{O}_2]}{dt} \).
insert step 5: Interpret the results: The average rate gives an overall rate of reaction over a time interval, while the instantaneous rate provides the rate at a specific moment in time.
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Reaction Rate
The reaction rate is a measure of how quickly reactants are converted into products in a chemical reaction. It can be expressed as the change in concentration of a reactant or product over a specific time interval. Understanding both average and instantaneous rates is crucial for analyzing reaction kinetics, as they provide insights into the speed and mechanism of the reaction.
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02:03
Average Rate of Reaction
Average Rate of Reaction
The average rate of reaction is calculated by taking the change in concentration of a reactant or product over a defined time period. For the reaction given, it involves determining the difference in concentration of H2O2 between 10 and 20 seconds and dividing it by the time interval. This provides a general overview of how fast the reaction occurs over that specific timeframe.
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02:03Average Rate of Reaction
Instantaneous Rate of Reaction
The instantaneous rate of reaction refers to the rate at a specific moment in time, often determined by the slope of the concentration vs. time graph at that point. For the reaction at 30 seconds, this involves finding the tangent to the curve at that time, which reflects the rate of change of concentration of H2O2 at that exact moment, providing a more precise understanding of the reaction dynamics.
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Related Practice
Textbook Question
Consider the reaction: H2( g) + Br2( g) → 2 HBr( g) The graph shows the concentration of Br2 as a function of time.
b. Make a rough sketch of a curve representing the concentration of HBr as a function of time. Assume that the initial concentration of HBr is zero
Textbook Question
Consider the reaction: 2 H2O2(aq) → 2 H2O(l ) + O2( g) The graph shows the concentration of H2O2 as a function of time.
Use the graph to calculate each quantity: c. the instantaneous rate of formation of O2 at 50 s
Textbook Question
Consider the reaction: 2 H2O2(aq) → 2 H2O(l ) + O2( g) The graph shows the concentration of H2O2 as a function of time. Use the graph to calculate each quantity: d. If the initial volume of the H2O2 is 1.5 L, what total amount of O2 (in moles) is formed in the first 50 s of reaction?
Textbook Question
This graph shows a plot of the rate of a reaction versus the concentration of the reactant A for the reaction A → products. a. What is the order of the reaction with respect to A?