The standard solution of FeSCN2+ (prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN) has an absorbance of 0.550. If a trial's absorbance is measured to be 0.350 and its initial concentration of SCN– was 0.0010 M, the equilibrium concentration of SCN– will be what?
To determine the equilibrium concentration of SCN- in this case, we can use the concept of Beer's Law. Beer's Law states that the concentration of a substance is directly proportional to its absorbance.
Given that the standard solution had an absorbance of 0.550 and the trial solution had an absorbance of 0.350, we can calculate the concentration ratio between the two solutions.
Absorbance standard solution / Absorbance trial solution = Concentration standard solution / Concentration trial solution
0.550 / 0.350 = Concentration standard solution / 0.0010 M
To find the equilibrium concentration of SCN- in the trial solution, we rearrange the equation:
Concentration trial solution = (0.550 / 0.350) * 0.0010 M
Concentration trial solution = 1.5714 * 0.0010 M
Concentration trial solution = 0.0016 M
Therefore, the equilibrium concentration of SCN- in the trial solution is 0.0016 M.