Assignment:
A 25.00 mL sample containing Cu2+ gave an instrument signal of 23.6 units (corrected for a blank). When exactly 0.500 mL of 0.0287 M Cu(NO3)2 was added to this solution, the signal increased to 37.9 units. Calculate the molar concentration of Cu2+ assuming that the signal was directly proportional to the analyze concentration.
Provide complete and step by step solution for the question and show calculations and use formulas.