Help with Beer's Law lab experiment question! So we were told to calculate the concentration of 5 standard solutions but I don't know how to do that exactly. The Concentration of the solution in flask B was .0024 M and our lambda max (max absorption) was at 515 nm. I know the formulas but I'm confused as to where to start first and how. I'd appreciate if someone could show me one example from the five below.

Vol. of B solution % transmittance
25mL 31
20mL 42
15mL 55
10mL 67
5mL 82

1 answer

For #1, did you take 25 mL of 0.0024 M and dilute it to some volume? What volume? The concn will be
0.0024M x (25 mL/final volume)= ?? M

After you know concn, then
A = log (1/T) = a*c (assuming the path length was the same throughout and it probably was). Knowing T and c you can calculate the constant, a for each of the five and calculate an average for a.