Here\'s part a\'s graph, I just need help with how to do part b. Suppose a kinet

Question

Here's part a's graph, I just need help with how to do part b.

Suppose a kinetic analysis was performed using absorbance spectroscopy and these were the data for the standard (A1) and the unknown (A2) as a function of time. Time (min A1 A2. 0.012 -0.022 0.105 0.166 2 0.346 0.23 3 0.444 0.36 0.553 0.419 0.5022 0.67 0573 6 0.678 7 0.606 0.753 0.664 8 0.831 9 0.704 0.861 a) Plot absorbance vs. time for the standard and unknown on the same graph. Label the axes. b) If the concentration of the standard was 1.63x10 4 M, calculate the concentration of the unknown

Explanation / Answer

By applying Beer's law one can calculate the concentration.

The equation for Beer's law is: A = mCl where, (A=absorbance, m = molar extinction coefficient, C = concentration, l=path length of 1 cm)

You'll need to add a line of best fit to the data points and determine the equation for the line. The equation should be in y=mx + b.

y = absorbance (A), x = concentration , m = (m) = slope or the molar extinction coefficient in beers law which has units of M1cm1

So A = mC +b

for concentartion C you should get
C = (A-b)/m

So if you substract your y-intercept from the absorbance and divide by the slope, you are finding the concentration of your sample

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