Molarity & dilution worksheet with answers

Free printable Molarity & dilution worksheet: 6 problems from easy to exam level, with an answer key. Print it or save it as a PDF.

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1.Easy
11.5 g KMnO4​V = 200 mL

11.5 g of KMnO4 (M = 158.03 g/mol) is dissolved in water to make 200 mL of solution. Find the molarity c.

m = 11.5 gM = 158.03 g/molV = 200 mL
c = mol/L
2.Easy
23.5 g KNO3​V = 750 mL

23.5 g of KNO3 (M = 101.1 g/mol) is dissolved in water to make 750 mL of solution. Find the molarity c.

m = 23.5 gM = 101.1 g/molV = 750 mL
c = mol/L
3.Medium
4 mol/LV1​ = ?0.5 mol/L100 mL

You need 100 mL of 0.5 mol/L solution and have a 4 mol/L stock solution. What volume V1 of stock solution do you need?

c1 = 4 mol/Lc2 = 0.5 mol/LV2 = 100 mL
V1 = mL
4.Medium
2 mol/LV1​ = ?0.05 mol/L200 mL

You need 200 mL of 0.05 mol/L solution and have a 2 mol/L stock solution. What volume V1 of stock solution do you need?

c1 = 2 mol/Lc2 = 0.05 mol/LV2 = 200 mL
V1 = mL
5.Hard
0.4 mol/L100 mL0.05 mol/L200 mLc = ?300 mL

100 mL of a 0.4 mol/L solution is mixed with 200 mL of a 0.05 mol/L solution of the same substance. Find the concentration c of the mixture (volumes are additive).

c1 = 0.4 mol/LV1 = 100 mLc2 = 0.05 mol/LV2 = 200 mL
c = mol/L
6.Hard
0.5 mol/L300 mL2.5 mol/L200 mLc = ?500 mL

300 mL of a 0.5 mol/L solution is mixed with 200 mL of a 2.5 mol/L solution of the same substance. Find the concentration c of the mixture (volumes are additive).

c1 = 0.5 mol/LV1 = 300 mLc2 = 2.5 mol/LV2 = 200 mL
c = mol/L

Answer key

  1. 1. c = 0.3639 mol/L
  2. 2. c = 0.3099 mol/L
  3. 3. V1 = 12.5 mL
  4. 4. V1 = 5 mL
  5. 5. c = 0.1667 mol/L
  6. 6. c = 1.3 mol/L

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