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
13.5 g NaClV = 200 mL

13.5 g of NaCl (M = 58.44 g/mol) is dissolved in water to make 200 mL of solution. Find the molarity c.

m = 13.5 gM = 58.44 g/molV = 200 mL
c = mol/L
2.Easy
28.5 g CuSO4​V = 500 mL

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

m = 28.5 gM = 159.61 g/molV = 500 mL
c = mol/L
3.Medium
2 mol/LV1​ = ?0.5 mol/L100 mL

You need 100 mL of 0.5 mol/L solution and have a 2 mol/L stock solution. What volume V1 of stock solution do you need?

c1 = 2 mol/Lc2 = 0.5 mol/LV2 = 100 mL
V1 = mL
4.Medium
4 mol/LV1​ = ?0.3 mol/L1000 mL

You need 1000 mL of 0.3 mol/L solution and have a 4 mol/L stock solution. What volume V1 of stock solution do you need?

c1 = 4 mol/Lc2 = 0.3 mol/LV2 = 1000 mL
V1 = mL
5.Hard
0.1 mol/L50 mL3 mol/L500 mLc = ?550 mL

50 mL of a 0.1 mol/L solution is mixed with 500 mL of a 3 mol/L solution of the same substance. Find the concentration c of the mixture (volumes are additive).

c1 = 0.1 mol/LV1 = 50 mLc2 = 3 mol/LV2 = 500 mL
c = mol/L
6.Hard
0.4 mol/L250 mL0.6 mol/L50 mLc = ?300 mL

250 mL of a 0.4 mol/L solution is mixed with 50 mL of a 0.6 mol/L solution of the same substance. Find the concentration c of the mixture (volumes are additive).

c1 = 0.4 mol/LV1 = 250 mLc2 = 0.6 mol/LV2 = 50 mL
c = mol/L

Answer key

  1. 1. c = 1.155 mol/L
  2. 2. c = 0.3571 mol/L
  3. 3. V1 = 25 mL
  4. 4. V1 = 75 mL
  5. 5. c = 2.736 mol/L
  6. 6. c = 0.4333 mol/L

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