This document calculates the concentrations of ions remaining after mixing solutions containing magnesium nitrate and sodium hydroxide. It first calculates the molarities of the reactants and uses the solubility product constant to determine the solubility of magnesium hydroxide. It then determines the final concentrations of magnesium, nitrate, sodium, and hydroxide ions are 1.65x10^-4 M, 0.4 M, 0.563 M, and 3.3x10^-4 M, respectively.