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
6 g KNO3​V = 250 mL

6 g of KNO3 (M = 101.1 g/mol) is dissolved in water to make 250 mL of solution. Find the molarity c.

m = 6 gM = 101.1 g/molV = 250 mL
c = mol/L
2.Easy
17.5 g CaCl2​V = 1000 mL

17.5 g of CaCl2 (M = 110.98 g/mol) is dissolved in water to make 1000 mL of solution. Find the molarity c.

m = 17.5 gM = 110.98 g/molV = 1000 mL
c = mol/L
3.Medium
0.5 mol/LV1​ = ?0.4 mol/L250 mL

You need 250 mL of 0.4 mol/L solution and have a 0.5 mol/L stock solution. What volume V1 of stock solution do you need?

c1 = 0.5 mol/Lc2 = 0.4 mol/LV2 = 250 mL
V1 = mL
4.Medium
1.5 mol/LV1​ = ?0.1 mol/L250 mL

You need 250 mL of 0.1 mol/L solution and have a 1.5 mol/L stock solution. What volume V1 of stock solution do you need?

c1 = 1.5 mol/Lc2 = 0.1 mol/LV2 = 250 mL
V1 = mL
5.Hard
0.2 mol/L150 mL1.2 mol/L400 mLc = ?550 mL

150 mL of a 0.2 mol/L solution is mixed with 400 mL of a 1.2 mol/L solution of the same substance. Find the concentration c of the mixture (volumes are additive).

c1 = 0.2 mol/LV1 = 150 mLc2 = 1.2 mol/LV2 = 400 mL
c = mol/L
6.Hard
2 mol/L50 mL2.5 mol/L100 mLc = ?150 mL

50 mL of a 2 mol/L solution is mixed with 100 mL of a 2.5 mol/L solution of the same substance. Find the concentration c of the mixture (volumes are additive).

c1 = 2 mol/LV1 = 50 mLc2 = 2.5 mol/LV2 = 100 mL
c = mol/L

Answer key

  1. 1. c = 0.2374 mol/L
  2. 2. c = 0.1577 mol/L
  3. 3. V1 = 200 mL
  4. 4. V1 = 16.67 mL
  5. 5. c = 0.9273 mol/L
  6. 6. c = 2.333 mol/L

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