Molarity practice problems

Chemistry Unit 4. Try each one, then open the worked solution. The Credit Sprint app generates unlimited new versions with fresh numbers.

Problem 1.

33 g of H₂SO₄ (98.08 g/mol) is dissolved to make 0.25 L of solution. What is the molarity?

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n = 33 ÷ 98.08 = 0.336 mol; M = n ÷ V = 0.336 ÷ 0.25 = 1.35 M.

Problem 2.

4 g of H₂SO₄ (98.08 g/mol) is dissolved to make 2 L of solution. What is the molarity?

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n = 4 ÷ 98.08 = 0.0408 mol; M = n ÷ V = 0.0408 ÷ 2 = 0.0204 M.

Problem 3.

33 g of NaOH (40 g/mol) is dissolved to make 0.25 L of solution. What is the molarity?

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n = 33 ÷ 40 = 0.825 mol; M = n ÷ V = 0.825 ÷ 0.25 = 3.3 M.

Problem 4.

32 g of H₂O (18.02 g/mol) is dissolved to make 0.25 L of solution. What is the molarity?

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n = 32 ÷ 18.02 = 1.78 mol; M = n ÷ V = 1.78 ÷ 0.25 = 7.1 M.

Problem 5.

31 g of H₂SO₄ (98.08 g/mol) is dissolved to make 2 L of solution. What is the molarity?

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n = 31 ÷ 98.08 = 0.316 mol; M = n ÷ V = 0.316 ÷ 2 = 0.158 M.

Problem 6.

39 g of NaOH (40 g/mol) is dissolved to make 0.5 L of solution. What is the molarity?

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n = 39 ÷ 40 = 0.975 mol; M = n ÷ V = 0.975 ÷ 0.5 = 1.95 M.