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Name: _____________ANSWER KEY__________________ Date: ________________________ Period: ______

Expanding on Molarity – Learning About Dilutions

1) If I add 25 mL of water to 125 mL of a 0.15 M NaOH solution, what will the molarity of the diluted solution be?

M1V1 = M2V2

(0.15 M)(125 mL) = x (150 mL)

x = 0.13 M

2) If I add water to 100 mL of a 0.15 M NaOH solution until the final volume is 150 mL, what will the molarity of the diluted solution be?

M1V1 = M2V2

(0.15 M)(100 mL) = x (150 mL)

x = 0.1 M

3) How much 0.05 M HCl solution can be made by diluting 250 mL of 10 M HCl?

M1V1 = M2V2

(10 M)(250 mL) = (0.05 M) x

x = 50,000 mL

4) I have 345 mL of a 1.5 M NaCl solution. If I boil the water until the volume of the solution is 250 mL, what will the molarity of the solution be?

M1V1 = M2V2

(1.5 M)(345 mL) = x (250 mL)

x = 2.1 M

5) How much water would I need to add to 500 mL of a 2.4 M KCl solution to make a 1.0 M solution?

M1V1 = M2V2

(2.4 M)(500 mL) = (1.0 M) x

x = 1200 mL

1200 mL will be the final volume of the solution. However, since there’s already 500 mL of solution present, you only need to add 700 mL of water to get 1200 mL as your final volume. The answer: 700 mL.

6) A stock solution of sodium sulfate, Na2SO4 has a concentration of 1.00 M. The volume of this solution is 50 mL. What volume of a 0.25 M solution could be made from the stock solution?

M1V1 = M2V2

(1.00 M)(50 mL) = (0.25 M) x

x = 200 mL

7) 2.00 mL of a 0.75 M solution of potassium permanganate, KMnO4 solution is used to make a 500...

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