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Rate of reaction, rate constants, and Arrhenius' Equation 
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#1
Sep2509, 06:39 PM

P: 34

1. The problem statement, all variables and given/known data
The effect of temperature on the rate of a reaction was studied and the following data obtained: k (s1) T (°C) 3.06×104 10 4.84×104 16 6.50×104 20 1.40×103 31 2.87×103 42 4.16×103 48 5.94×103 54 7.92×103 59 It is known that the variation of the rate constant k with the absolute temperature T is described by the Arrhenius equation: k = A exp^[( Ea )/(RT)] where Ea is the activation energy, R is the universal gas constant and A is the preexponential factor (units of the rate constant). Taking the natural logarithm of both sides affords: ln k = ln A  Ea/RT a) For a plot of y = ln k versus x = 1/T, calculate the slope of the best straight line using linear regression. b) Calculate the activation energy Ea. 2. Relevant equations Relevant equations listed in part 1 3. The attempt at a solution Do I need to plot this data? Is there any way to do this without using excel or a graphing calculator? If there isn't, I tried putting these in a spreadsheet, then plot ln k in the y axis and 1/T on the x axis and then use Excel's "trendline" to get the slope. (The slope is Ea/R. So Ea is R x slope for part 2). However, I got 38.619 for the slope.. although, I dont know if this is right or wrong as I seem to keep getting the units wrong, are the not the units for (ln k)/(1/T), which is s^(1)/degC^(1), or degC/s??? (where degC = degrees celcius) If there is another way to figure this out, and if you know why I am getting the wrong units, help would be greatly appreciated! Once I know the first part, part b is a cinch. Thankyou! 


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