Math Problem Statement

T(c) k(s-1) 190 0.000025 199 0.000053 215 0.00025 230 0.00063 248 0.0032 plot this graph and determine activation energy in units kj/mol

Solution

To plot the given data and calculate the activation energy, we need to follow these steps:

  1. Understand the relationship: The data suggests that T(c)T(c) corresponds to temperature in Celsius, and k(s1)k(s-1) is the rate constant (presumably in units of s1s^{-1}).

  2. Use the Arrhenius equation:
    The Arrhenius equation expresses the temperature dependence of reaction rates as:

    k=AeEaRTk = A \cdot e^{-\frac{E_a}{RT}}

    Where:

    • kk is the rate constant,
    • AA is the pre-exponential factor,
    • EaE_a is the activation energy,
    • RR is the gas constant (8.314 J/mol·K),
    • TT is the temperature in Kelvin.

    To find the activation energy EaE_a, we take the natural logarithm of both sides of the equation:

    ln(k)=ln(A)EaR1T\ln(k) = \ln(A) - \frac{E_a}{R} \cdot \frac{1}{T}

    This is a linear equation of the form y=mx+by = mx + b, where:

    • y=ln(k)y = \ln(k),
    • x=1Tx = \frac{1}{T},
    • m=EaRm = -\frac{E_a}{R} (the slope).
  3. Steps to calculate activation energy:

    • Convert the temperature from Celsius to Kelvin by adding 273.15.
    • Plot ln(k)\ln(k) vs. 1T\frac{1}{T}.
    • Determine the slope of the line, which will give us EaR-\frac{E_a}{R}.
    • Solve for EaE_a.

I’ll now plot the graph and calculate the activation energy.

Let me first plot the data. numpy as np import matplotlib.pyplot as plt

Given data

T_celsius = np.array([190, 199, 215, 230, 248]) # Temperature in Celsius k_s_1 = np.array([0.000025, 0.000053, 0.00025, 0.00063, 0.0032]) # Rate constant (s^-1)

Convert temperature to Kelvin

T_kelvin = T_celsius + 273.15

Calculate 1/T and ln(k)

inv_T = 1 / T_kelvin ln_k = np.log(k_s_1)

Plotting the graph of ln(k) vs. 1/T

plt.figure(figsize=(8, 6)) plt.plot(inv_T, ln_k, 'o-', label="Data points", color='b') plt.title("Arrhenius Plot: ln(k) vs. 1/T") plt.xlabel("1/T (1/K)") plt.ylabel("ln(k)") plt.grid(True) plt.legend() plt.show()The plot above shows the relationship between ln(k)\ln(k) and 1T\frac{1}{T}. To calculate the activation energy, we need to determine the slope of the line, which corresponds to EaR-\frac{E_a}{R}.

Let me now calculate the slope and determine the activation energy EaE_a. Perform linear regression to find the slope (m) and intercept (b) slope, intercept = np.polyfit(inv_T, ln_k, 1)

Calculate the activation energy (E_a) in Joules per mole

R = 8.314 # Gas constant in J/mol·K E_a_Joules_per_mol = -slope * R # E_a = -slope * R

Convert activation energy from Joules to kilojoules (1 kJ = 1000 J)

E_a_kJ_per_mol = E_a_Joules_per_mol / 1000

E_a_kJ_per_molThe activation energy EaE_a is approximately 166 kJ/mol.

Would you like more details on the calculations, or have any further questions about this?

Here are some related questions you might find helpful:

  1. How can I interpret the results of an Arrhenius plot in terms of reaction kinetics?
  2. What does the pre-exponential factor AA represent in the Arrhenius equation?
  3. How can temperature affect the rate constant kk in chemical reactions?
  4. What are common units for activation energy and rate constants in chemical kinetics?
  5. How would the activation energy change if the reaction took place at a different temperature range?

Tip: Always ensure temperatures are in Kelvin when using the Arrhenius equation, as it's essential for accurate calculations.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Arrhenius Equation
Linear Regression
Logarithms
Temperature Conversion

Formulas

Arrhenius equation: k = A * e^(-Ea / RT)
ln(k) = ln(A) - (Ea / R) * (1 / T)

Theorems

Arrhenius Law
Linear Regression Theory

Suitable Grade Level

Undergraduate (Chemistry, Physical Chemistry)