The accompanying graph shows plots of ln k versus 1/𝑇 for two different reactions. The plots have been extrapolated to the y-intercepts. Which reaction (red or blue) has b. the larger value for the frequency factor, A? [Section 14.4]

Video transcript

Hi everyone. This problem reads the following graph is an Iranian plot for two different chemical reactions marked reaction one and reaction to determine which one of the two reactions has a smaller value of the pre exponential factor. A. Okay, so we have an Iranian plot so we need to write out our Iranian equation and its linear form. Okay. And the Iranian equation and its linear form is Ln of K. Is equal to negative activation energy over gas constant R times one over temperature plus Ln of A. And let's remember that the Iranians equation shows the relationship between temperature and the rate constant K. Okay, so if we translate this to a equation for a straight line, the equation we're going to get is Y equals M X plus B. So this is our Iranians equation in linear form. And let's take a look at our Y intercept. Okay, our Y intercept equals Ln of A. Okay, so here B equals Ln of A. And when we look at the Y intercept on our plot, we see that reaction to has a smaller value of the Y intercept than reaction one. Okay, so that means the Ln of A should also be smaller for reaction to which tells us that reaction to has a smaller frequency factor. Okay, so we're right out here. Reaction number two equals the smaller frequency factor. Okay, and that is it for this problem. I hope that this was helpful