Textbook Question
The diagram shows the energy of a reaction as the reaction progresses. Label each blank box in the diagram.
a. reactants b. products c. activation energy (Ea) d. enthalpy of reaction (ΔHrxn)
2043
views
Ch.14 - Chemical Kinetics
Chapter 14, Problem 63
The rate constant (k) for a reaction was measured as a function of temperature. A plot of ln k versus 1/T (in K) is linear and has a slope of -7445 K. Calculate the activation energy for the reaction.
Verified Solution
Video duration:
0m:0s
This video solution was recommended by our tutors as helpful for the problem above.Was this helpful?
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Arrhenius Equation
The Arrhenius equation relates the rate constant (k) of a chemical reaction to the temperature (T) and activation energy (Ea). It is expressed as k = A * e^(-Ea/RT), where A is the pre-exponential factor, R is the universal gas constant, and T is the temperature in Kelvin. This equation shows that as temperature increases, the rate constant typically increases, indicating a faster reaction.
Recommended video:
Guided course
01:20
Arrhenius Equation
Activation Energy (Ea)
Activation energy is the minimum energy required for a chemical reaction to occur. It represents the energy barrier that reactants must overcome to form products. A higher activation energy means that fewer molecules have sufficient energy to react at a given temperature, resulting in a slower reaction rate. It can be determined from the slope of a plot of ln k versus 1/T.
Recommended video:
Guided course
02:02Activity Series Chart
Linear Relationship in ln k vs. 1/T
The linear relationship between ln k and 1/T indicates that the reaction follows the Arrhenius behavior. The slope of this line is equal to -Ea/R, where R is the gas constant. This linearity allows for the calculation of activation energy by rearranging the equation to Ea = -slope * R. In this case, the slope of -7445 K can be used to find the activation energy for the reaction.
Recommended video:
Guided course
02:43Relationship between ∆E°, ∆G°, and K
Related Practice
Textbook Question
The activation energy of a reaction is 56.8 kJ/mol and the frequency factor is 1.5⨉1011/ s. Calculate the rate constant of the reaction at 25 °C.
2935
views
1
comments
Open Question
The rate constant of a reaction at 32 °C is 0.055 s⁻¹. If the frequency factor is 1.2 × 10¹³ s⁻¹, what is the activation barrier?
Open Question
The rate constant (k) for a reaction was measured as a function of temperature. A plot of ln k versus 1/T (in K) is linear and has a slope of -1.01 * 10^4 K. Calculate the activation energy for the reaction.
Textbook Question
The data shown here were collected for the first-order reaction: N2O(g) → N2(g) + O(g) Use an Arrhenius plot to determine the activation barrier and frequency factor for the reaction.
Temperature (K) Rate Constant (1 , s)
800 3.24⨉10- 5
900 0.00214
1000 0.0614
1100 0.955
1575
views
Textbook Question
The tabulated data show the rate constant of a reaction measured at several different temperatures. Use an Arrhenius plot to determine the activation barrier and frequency factor for the reaction.
Temperature (K) Rate Constant (1 , s)
300 0.0134
310 0.0407
320 0.114
330 0.303
340 0.757
2534
views