Multiple Choice
The activation energy for the decomposition of HI(g) to H2(g) and I2(g) is 186 kJ/mol. The rate constant at 555 K is 3.52 × 10^-7 L/mol-s. What is the rate constant at 645 K?
15. Chemical Kinetics
Arrhenius Equation
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Join thousands of students who trust us to help them ace their exams!Watch the first videoMultiple Choice
Using the Arrhenius Equation, what is the rate constant (k) for the reaction of NO with F2 at a temperature of 298 K?
A
4.56 × 10^6 M⁻¹⋅s⁻¹
B
1.23 × 10^7 M⁻¹⋅s⁻¹
C
2.45 × 10^8 M⁻¹⋅s⁻¹
D
5.67 × 10^8 M⁻¹⋅s⁻¹
Verified step by step guidance1
Identify the Arrhenius Equation: \( k = A e^{-\frac{E_a}{RT}} \), where \( k \) is the rate constant, \( A \) is the pre-exponential factor, \( E_a \) is the activation energy, \( R \) is the gas constant, and \( T \) is the temperature in Kelvin.
Determine the values needed: You need the activation energy \( E_a \), the pre-exponential factor \( A \), and the temperature \( T \). The temperature is given as 298 K. The values for \( A \) and \( E_a \) are typically provided in the problem or can be found in literature.
Convert the activation energy \( E_a \) to the appropriate units if necessary. It is often given in kJ/mol, so you may need to convert it to J/mol by multiplying by 1000.
Substitute the known values into the Arrhenius Equation. Use \( R = 8.314 \) J/(mol·K) for the gas constant.
Calculate the exponential term \( e^{-\frac{E_a}{RT}} \) and then multiply by the pre-exponential factor \( A \) to find the rate constant \( k \).
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