1. When 7 mL of a solution containing 2.7 M AlBr3 is diluted to 33 mL, a dilute solution is formed. What is the Br- concentration in 15 mL of the dilute solution?
2. A stock solution is prepared by adding 28 mL of 1.4000000000000004 M Na3PO4 to enough water to make 76 mL. What is the PO43- concentration of 50 mL of the stock solution?