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Ch.15 - Chemical Kinetics

Chapter 15, Problem 67

The activation energy of a reaction is 44.2 kJ/mol and the frequency factor is 1.9⨉1011/ s. Calculate the rate constant of the reaction at 25 °C.

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Hi everyone for this problem. We're being asked to calculate the rate constant for a reaction that has an activation energy of 45. kg per mole and a frequency factor of 2. times 10 to the 10 At 38°C. Okay, so let's start off by writing out our our equation that we're going to need to solve for this problem. And that is our rate constant is equal to our frequency factor times our negative activation energy over r universal gas constant times our temperature. Okay, so this is what we're going to use to solve this. Let's take a look at what we're given. So our activation energy is 45.8 kg joules per mole. We need to convert this to jules per mole. Okay, so our activation energy Is 45.8 kg joules per mole. And to go from killer jewels, promoter joules per mole will use one. Kill a jewel Is equal to jewels. So this gives us an activation energy of 4.58 times 10 to the four jewels Permal secondly, we're given our temperature and C but we need to convert it to Kelvin. So our temperature is equal to 38°C. And to go to Kelvin we add 273.15. So we get a temperature of four. Sorry we got a temperature of .15 Kelvin. So that is all that we needed to convert. And so let's go ahead and plug in. So our Frequency factor was given, were told that it is 2.38 times 10 to the And then we have to, we have to put a negative in front of our activation energy. So we get negative 4. Times 10 to the 4th jewels per mole. And this is all over our universal gas constant, which is a value we should know. And that is 8. 314 8.314 jewels Over Mole Times Kelvin. And this is multiplied by our temperature in Kelvin 311. Kelvin. So we have everything that we need to solve four, our rate constant. And when we solve this problem, we get a final answer of K is equal to 4.90 times to the second seconds and verse. And this is our final answer. Okay, that's the end of this problem. I hope this was helpful.