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.

New worksheetPractise online with hints

For teachers: free to print, copy and use in class. Every new worksheet has new values and its own answer key. A link to ExamProblems on your course page is appreciated.

Name: ____________________   Date: ____________

1.Easy
40 g KMnO4​V = 250 mL

40 g of KMnO4 (M = 158.03 g/mol) is dissolved in water to make 250 mL of solution. Find the molarity c.

m = 40 gM = 158.03 g/molV = 250 mL
c = mol/L
2.Easy
200 mLc = 1 mol/L

What mass m of KMnO4 (M = 158.03 g/mol) do you need to make 200 mL of a 1 mol/L solution?

V = 200 mLc = 1 mol/LM = 158.03 g/mol
m = g
3.Medium
6 mol/LV1​ = ?0.2 mol/L100 mL

You need 100 mL of 0.2 mol/L solution and have a 6 mol/L stock solution. What volume V1 of stock solution do you need?

c1 = 6 mol/Lc2 = 0.2 mol/LV2 = 100 mL
V1 = mL
4.Medium
4 mol/LV1​ = ?0.2 mol/L1000 mL

You need 1000 mL of 0.2 mol/L solution and have a 4 mol/L stock solution. What volume V1 of stock solution do you need?

c1 = 4 mol/Lc2 = 0.2 mol/LV2 = 1000 mL
V1 = mL
5.Hard
0.5 mol/L100 mL2.5 mol/L200 mLc = ?300 mL

100 mL of a 0.5 mol/L solution is mixed with 200 mL of a 2.5 mol/L solution of the same substance. Find the concentration c of the mixture (volumes are additive).

c1 = 0.5 mol/LV1 = 100 mLc2 = 2.5 mol/LV2 = 200 mL
c = mol/L
6.Hard
2 mol/L250 mL2.5 mol/L200 mLc = ?450 mL

250 mL of a 2 mol/L solution is mixed with 200 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 = 250 mLc2 = 2.5 mol/LV2 = 200 mL
c = mol/L

Answer key

  1. 1. c = 1.012 mol/L
  2. 2. m = 31.61 g
  3. 3. V1 = 3.333 mL
  4. 4. V1 = 50 mL
  5. 5. c = 1.833 mol/L
  6. 6. c = 2.222 mol/L

Full step-by-step solutions: practise this topic on examproblems.com.