Posted by eve on Sunday, April 19, 2009 at 10:30pm.
An unknown was prepared with the concentration of 0.000630 M. A Beer's Law plot was prepared using the absorbance values from standard solutions of ASA and a line drawn through all the points passed through the origin with a slope of 1550.2 M–1 . The expected absorbance and %T values for the diluted aspirin solution prepared by the student is _______ and __________, respectively.

chem  DrBob222, Sunday, April 19, 2009 at 10:38pm
I worked this about an two hours ago. Perhaps for another student.
Normally, the concn curves for spectrophotometric work is done by plotting A (absorbance) on the Y axis and c (concn) on the x axis.
Since you have a straight line, the equation for a straight line is
y = mx + b where m is the slope and b is the y intercept. Since the line passes through the origin, b=0 and the equation becomes y = mx
Changing to the way graphs are made, this beomes A = m*c. The slope in the problem (m) is 1550.2; therefore, the equation becomes
A=1550.2*c.
You have c, calculate A(bsorbance). For transmittance, remember that A = log (1/T) or if you want it in %T directly it is A = log (100/%T)