A solution contains 23.1 ppm of dissolved Fe(NO3)3 (241.860g/mol), which dissociates completely into Fe3+ and NO3- (62.005g/mol) ions. Find the concentration of NO3- in parts per million

Question

A solution contains 23.1 ppm of dissolved Fe(NO3)3 (241.860g/mol), which dissociates completely into Fe3+ and NO3- (62.005g/mol) ions.  Find the concentration of NO3- in parts per million

DrBob222 · Answer

For every one Fe(NO3)3 molecule you have you get three NO3^- ions when the molecule dissociates. So the (NO3^-) is 23.1 ppm x 3 = ?