1. When 15 mL of a solution containing .29 M Ca(OH)2 is diluted to 32 mL, a dilute solution is formed. What is the OH- concentration in 5 mL of the dilute solution?
2. A 110 mL stock solution contains 7 M BaCl2. When 27 mL of the stock solution is diluted to 75 mL, how many moles of Ba2+ ions will be contained in the dilute solution?
3. A stock solution is prepared by adding 23 mL of 2.1 M Na2SO4 to enough water to make 40 mL. How many moles of Na+ are in 15 mL of the stock solution?