Question

1) (a) Calculate the molarity of a solution made by dissolving 12.5 grams of Na2CrO4 on enough water to form exactly 550 ml of solution. (b) How many moles of KBr arepresent in 150 ml of a 0.275 M solution? (c) How many milliliters of 6.1 M HCI solution are needed to obtain 0.100 mol of HCI?

2) (a) How many grams of solute are persent in 15.0 ml of 0.736 M K2Cr2O7 ? (b) if 14.00 g of (NH4)2SO4 is dissolved in enough water to form 250 ml of solution, whatis the molarity of the solution? (c) How many milliliters of 0.0455 M CuSO4 contain 3.65 g solute?

3) (a) How many milliliter of a stock solution of 6.0 M HNO3 would you have to use to perpare 110 ml of 0.500 M HNO3? (b) If you dilute 10.0 ml of the stock solutionto a final volume of 0.250 L, what will be the concentration of the diluted solution?

Answer 1

500 ml x 1L/1000ml= .50 L

12.5 g Na2CrO4 x 1 mole/162 g NaCrO4= .077 moles

.077 moles/.50 L = .154 M