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
30.5 g CuSO4​V = 150 mL

30.5 g of CuSO4 (M = 159.61 g/mol) is dissolved in water to make 150 mL of solution. Find the molarity c.

m = 30.5 gM = 159.61 g/molV = 150 mL
c = mol/L
2.Easy
33.5 g KNO3​V = 1000 mL

33.5 g of KNO3 (M = 101.1 g/mol) is dissolved in water to make 1000 mL of solution. Find the molarity c.

m = 33.5 gM = 101.1 g/molV = 1000 mL
c = mol/L
3.Medium
3 mol/LV1​ = ?0.1 mol/L100 mL

You need 100 mL of 0.1 mol/L solution and have a 3 mol/L stock solution. What volume V1 of stock solution do you need?

c1 = 3 mol/Lc2 = 0.1 mol/LV2 = 100 mL
V1 = mL
4.Medium
6 mol/LV1​0.05 mol/L250 mL

You need 250 mL of 0.05 mol/L solution and have a 6 mol/L stock solution. How much water Vwater do you add to the stock solution?

c1 = 6 mol/Lc2 = 0.05 mol/LV2 = 250 mL
Vwater = mL
5.Hard
2 mol/L150 mL0.3 mol/L250 mLc = ?400 mL

150 mL of a 2 mol/L solution is mixed with 250 mL of a 0.3 mol/L solution of the same substance. Find the concentration c of the mixture (volumes are additive).

c1 = 2 mol/LV1 = 150 mLc2 = 0.3 mol/LV2 = 250 mL
c = mol/L
6.Hard
0.1 mol/L300 mL2.5 mol/L250 mLc = ?550 mL

300 mL of a 0.1 mol/L solution is mixed with 250 mL of a 2.5 mol/L solution of the same substance. Find the concentration c of the mixture (volumes are additive).

c1 = 0.1 mol/LV1 = 300 mLc2 = 2.5 mol/LV2 = 250 mL
c = mol/L

Answer key

  1. 1. c = 1.274 mol/L
  2. 2. c = 0.3314 mol/L
  3. 3. V1 = 3.333 mL
  4. 4. Vwater = 247.9 mL
  5. 5. c = 0.9375 mol/L
  6. 6. c = 1.191 mol/L

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