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 KNO3​V = 250 mL

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

m = 30.5 gM = 101.1 g/molV = 250 mL
c = mol/L
2.Easy
7 g C6​H12​O6​V = 1000 mL

7 g of C6H12O6 (M = 180.16 g/mol) is dissolved in water to make 1000 mL of solution. Find the molarity c.

m = 7 gM = 180.16 g/molV = 1000 mL
c = mol/L
3.Medium
6 mol/LV1​ = ?0.25 mol/L1000 mL

You need 1000 mL of 0.25 mol/L solution and have a 6 mol/L stock solution. What volume V1 of stock solution do you need?

c1 = 6 mol/Lc2 = 0.25 mol/LV2 = 1000 mL
V1 = mL
4.Medium
1 mol/LV1​0.05 mol/L1000 mL

You need 1000 mL of 0.05 mol/L solution and have a 1 mol/L stock solution. How much water Vwater do you add to the stock solution?

c1 = 1 mol/Lc2 = 0.05 mol/LV2 = 1000 mL
Vwater = mL
5.Hard
0.4 mol/L200 mL0.3 mol/L400 mLc = ?600 mL

200 mL of a 0.4 mol/L solution is mixed with 400 mL of a 0.3 mol/L solution of the same substance. Find the concentration c of the mixture (volumes are additive).

c1 = 0.4 mol/LV1 = 200 mLc2 = 0.3 mol/LV2 = 400 mL
c = mol/L
6.Hard
0.4 mol/L200 mL0.3 mol/L100 mLc = ?300 mL

200 mL of a 0.4 mol/L solution is mixed with 100 mL of a 0.3 mol/L solution of the same substance. Find the concentration c of the mixture (volumes are additive).

c1 = 0.4 mol/LV1 = 200 mLc2 = 0.3 mol/LV2 = 100 mL
c = mol/L

Answer key

  1. 1. c = 1.207 mol/L
  2. 2. c = 0.03885 mol/L
  3. 3. V1 = 41.67 mL
  4. 4. Vwater = 950 mL
  5. 5. c = 0.3333 mol/L
  6. 6. c = 0.3667 mol/L

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