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
​
Required:
Use an Arrhenius plot to determine the activation barrier for the reaction.

Answer 1

To determine the activation barrier and frequency factor for the reaction using an Arrhenius plot, plot the natural logarithm of the rate constant against the reciprocal of the temperature. The slope of the line gives the activation barrier and the y-intercept gives the frequency factor.

Step-by-step explanation:

To determine the activation barrier and frequency factor for the reaction using an Arrhenius plot, you need to plot the natural logarithm of the rate constant (ln(k)) against the reciprocal of the temperature (1/T). This will give you a straight line with a negative slope. The activation barrier (Ea) can be determined from the slope of the line, which is equal to -Ea/R, where R is the gas constant. The frequency factor (A) can be determined from the y-intercept of the line.

First, calculate the reciprocal of the temperature for each data point. Then, take the natural logarithm of the rate constant for each data point. Plot ln(k) on the y-axis and 1/T on the x-axis. Determine the slope of the line and calculate -Ea. Determine the y-intercept of the line and calculate A.