To gravimetrically analyze the silver content of a piece of jewelry made from an alloy of Ag and Cu, a student dissolves a small preweighed sample in HNO3(aq). Ag+(aq)and Cu2+(aq) ions form in the solution. Which of the following should be the next step in the analytical process? a. Centrifuging the solution to isolate the heavier ions
b. Adding enough base solution to bring the pH up to 7.0
c. Adding a solution containing an anion that forms an insoluble salt with only one of the metal ions
d. Evaporating the solution to recover the dissolved nitrates