Wrap-Up

In this lesson you learned how to name acids and bases given their formulas and how to determine their formulas given the name.

You learned how the concentrations of acid and base solutions are expressed and calculated using both molarity and normality. You have also become familiar with the relationship between moles and equivalents and how these are used to determine molarity and normality, respectively.

You now know how to determine the concentration of a solution that results from dilution of a more concentrated solution and how to calculate the concentration of a solution from titration data. In the lab, you will perform a titration and use that data to determine the concentration of an unknown acid and then its equivalent mass.

Self Quiz

1. What is the normality of a solution containing 4.0 moles of H₃PO₄ dissolved in 2.0 L of solution?

2. What is the normality of a 0.24 M Ba(OH)₂ solution?

3. Calculate the equivalent mass of H₂C₂O₄, a diprotic acid.

4. You use 34.0 mL of 0.56 N acid to neutralize 1.20 g of a base. How many equivalents of base were present, and what is its equivalent mass?

5. How many equivalents are there in 3 moles of Mg(OH)₂?

6. What is the concentration in normal of an acid if 40.0 mL of it is titrated with 25.0 mL of 0.30 N base?

7. Complete and balance this equation and name the salt produced.
   HNO₂ (aq) + Ca(OH)₂ (aq) →

8. Write a balanced equation for the neutralization of aluminum hydroxide with sulfurous acid, and indicate the name of the salt produced.

Self Quiz Answers

1. What is the normality of a solution containing 4.0 moles of H₃PO₄ dissolved in 2.0 L of solution?
   4.0 mol * 3 eq/1 mol = 12 eq
   12 eq/2.0 L = 6.0 N

2. What is the normality of a 0.24 M Ba(OH)₂ solution?
   0.24 eq/L * 2 eq/1 mol = 0.48 eq/L = 0.48 N

3. Calculate the equivalent mass of H₂C₂O₄, a diprotic acid.
   Molar mass = 2*1.008 + 2*12.01 + 4*16.00 = 90.04 g/mol
   90.04 g/1 mol * 1 mol/2 eq = 45.02 g/eq

4. You use 34.0 mL of 0.56 N acid to neutralize 1.20 g of a base. How many equivalents of base were present, and what is its equivalent mass?
   0.56 eq/L *0.034 L = 0.019 eq acid → 0.019 eq base
   1.20 g/0.019 eq = 63.03 g/eq

5. How many equivalents are there in 3 moles of Mg(OH)₂?
   3 mol * 2 eq/1mol = 6 eq

6. What is the concentration in normal of an acid if 40.0 mL of it is titrated with 25.0 mL of 0.30 N base?
   C_AV_A = C_BV_B
   C_A = 0.30 N * 25.0 mL/40.0 mL = 0.188 N

7. Complete and balance this equation and name the salt produced.
   HNO₂ (aq) + Ca(OH)₂ (aq) → 2 H₂O (l) + Ca(NO₂)₂ (aq) calcium nitrite

8. Write a balanced equation for the neutralization of aluminum hydroxide with sulfurous acid, and indicate the name of the salt produced.
   Al(OH)₃ (aq) + H₂SO₃ (aq) → H₂O (l) + Al₂(SO₃)₃ (aq) aluminum sulfite