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
500 mLc = 1 mol/L

What mass m of CuSO4 (M = 159.61 g/mol) do you need to make 500 mL of a 1 mol/L solution?

V = 500 mLc = 1 mol/LM = 159.61 g/mol
m = g
2.Easy
3.5 g Na2​CO3​V = 750 mL

3.5 g of Na2CO3 (M = 105.99 g/mol) is dissolved in water to make 750 mL of solution. Find the molarity c.

m = 3.5 gM = 105.99 g/molV = 750 mL
c = mol/L
3.Medium
4 mol/LV1​0.05 mol/L200 mL

You need 200 mL of 0.05 mol/L solution and have a 4 mol/L stock solution. How much water Vwater do you add to the stock solution?

c1 = 4 mol/Lc2 = 0.05 mol/LV2 = 200 mL
Vwater = mL
4.Medium
2.5 mol/LV1​ = ?0.1 mol/L100 mL

You need 100 mL of 0.1 mol/L solution and have a 2.5 mol/L stock solution. What volume V1 of stock solution do you need?

c1 = 2.5 mol/Lc2 = 0.1 mol/LV2 = 100 mL
V1 = mL
5.Hard
0.8 mol/L50 mL0.3 mol/L500 mLc = ?550 mL

50 mL of a 0.8 mol/L solution is mixed with 500 mL of a 0.3 mol/L solution of the same substance. Find the concentration c of the mixture (volumes are additive).

c1 = 0.8 mol/LV1 = 50 mLc2 = 0.3 mol/LV2 = 500 mL
c = mol/L
6.Hard
2 mol/L300 mL2.5 mol/L100 mLc = ?400 mL

300 mL of a 2 mol/L solution is mixed with 100 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 = 300 mLc2 = 2.5 mol/LV2 = 100 mL
c = mol/L

Answer key

  1. 1. m = 79.81 g
  2. 2. c = 0.04403 mol/L
  3. 3. Vwater = 197.5 mL
  4. 4. V1 = 4 mL
  5. 5. c = 0.3455 mol/L
  6. 6. c = 2.125 mol/L

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