Hard water often contains dissolved Ca²⁺ and Mg²⁺ ions. One way to soften water is to add phosphates. The phosphate ion forms insoluble precipitates with calcium and magnesium ions, removing them from solution. A solution is 0.050 M in calcium chloride and 0.085 M in magnesium nitrate. What mass of sodium phosphate would you add to 1.5 L of this solution to completely eliminate the hard water ions? Assume complete reaction.

An acid solution is 0.100 M in HCl and 0.200 M in H₂SO₄. What volume of a 0.150 M KOH solution would completely neutralize all the acid in 500.0 mL of this solution?

Find the mass of barium metal (in grams) that must react with O₂ to produce enough barium oxide to prepare 1.0 L of a 0.10 M solution of OH^-.

A solution contains Cr³⁺ ions and Mg²⁺ ions. The addition of 1.00 L of 1.51 M NaF solution causes the complete precipitation of these ions as CrF₃(s) and MgF₂(s). The total mass of the precipitate is 49.6 g. Find the mass of Cr³⁺ in the original solution.

Treatment of gold metal with BrF₃ and KF produces Br₂ and KAuF₄, a salt of gold. Find the mass of the gold salt that forms when a 73.5-g mixture of equal masses of all three reactants is prepared.

Treatment of gold metal with BrF₃ and KF produces Br₂ and KAuF₄, a salt of gold. Identify the oxidizing agent and the reducing agent in this reaction.

A solution contains one or more of the following ions: Ag⁺ , Ca²⁺ , and Cu²⁺ . When you add sodium chloride to the solution, no precipitate forms. When you add sodium sulfate to the solution, a white precipitate forms. You filter off the precipitate and add sodium carbonate to the remaining solution, producing another precipitate. Write net ionic equations for the formation of each of the precipitates observed.

A solution contains one or more of the following ions: Hg₂²⁺, Ba²⁺, and Fe²⁺. When you add potassium chloride to the solution, a precipitate forms. The precipitate is filtered off, and you add potassium sulfate to the remaining solution, producing no precipitate. When you add potassium carbonate to the remaining solution, a precipitate forms. Write net ionic equations for the formation of each of the precipitates observed.

A hydrochloric acid solution will neutralize a sodium hydroxide solution. Look at the molecular views showing one beaker of HCl and four beakers of NaOH. Which NaOH beaker will just neutralize the HCl beaker? Begin by writing a balanced chemical equation for the neutralization reaction.