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
10.5 g NaClV = 1000 mL

10.5 g of NaCl (M = 58.44 g/mol) is dissolved in water to make 1000 mL of solution. Find the molarity c.

m = 10.5 gM = 58.44 g/molV = 1000 mL
c = mol/L
2.Easy
26 g CuSO4​V = 500 mL

26 g of CuSO4 (M = 159.61 g/mol) is dissolved in water to make 500 mL of solution. Find the molarity c.

m = 26 gM = 159.61 g/molV = 500 mL
c = mol/L
3.Medium
0.5 mol/LV1​ = ?0.4 mol/L200 mL

You need 200 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 = 200 mL
V1 = mL
4.Medium
1 mol/LV1​ = ?0.4 mol/L250 mL

You need 250 mL of 0.4 mol/L solution and have a 1 mol/L stock solution. What volume V1 of stock solution do you need?

c1 = 1 mol/Lc2 = 0.4 mol/LV2 = 250 mL
V1 = mL
5.Hard
2 mol/L50 mL0.6 mol/L100 mLc = ?150 mL

50 mL of a 2 mol/L solution is mixed with 100 mL of a 0.6 mol/L solution of the same substance. Find the concentration c of the mixture (volumes are additive).

c1 = 2 mol/LV1 = 50 mLc2 = 0.6 mol/LV2 = 100 mL
c = mol/L
6.Hard
0.25 mol/L200 mL0.6 mol/L250 mLc = ?450 mL

200 mL of a 0.25 mol/L solution is mixed with 250 mL of a 0.6 mol/L solution of the same substance. Find the concentration c of the mixture (volumes are additive).

c1 = 0.25 mol/LV1 = 200 mLc2 = 0.6 mol/LV2 = 250 mL
c = mol/L

Answer key

  1. 1. c = 0.1797 mol/L
  2. 2. c = 0.3258 mol/L
  3. 3. V1 = 160 mL
  4. 4. V1 = 100 mL
  5. 5. c = 1.067 mol/L
  6. 6. c = 0.4444 mol/L

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