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        Acid-base titration involves the gradual addition of acids and bases to one another, generally for
the purpose of determining reacting volumes or concentrations. In a laboratory titration, 1M HCl was
gradually added to 50 mL of 1M NaOH. The pH was monitored throughout the analysis, and the following
readings were obtained.

 VOLUME OF HCl            pH OF
   ADDED (mL)           SOLUTION
       0                   14.0
        5                  13.9
        10                 13.8
        15                 13.7
        20                 13.6
        30                 13.4
        40                 13.0
        45                 12.4
        49                 11.7
        50                 7.0
        51                 2.3
        55                 1.6
        60                 1.0
        75                 0.7
        100                0.64

Plot these data on the grid above, and then answer the following questions.

   1.   What volume of 1.0 M HCl was required to reach the equivalent point?

   2. How would the graph differ if the concentration of titrating HCl were increased to 2.0 M?

   3. List an indicator that could be used to recognize the equivalence point of this titration. Describe
      the color changes that the solution would undergo with the addition of HCl.

Titration Practice Problems: solve the following problems on a separate piece of paper or the back of
this worksheet.

   1.   What volume of 0.275 M hydrochloric acid solution reacts with 36.4 mL of 0.150 M sodium
        hydroxide solution? HCl + NaOH  NaCl + H2O

   2. What volume of 0.112 M NaOH solution would be required to react with 25.3 mL of 0.400 M
      H2SO4 solution? H2SO4 + 2NaOH  Na2SO4 + 2H2O

   3. A 0.08964 M solution of NaOH was used to titrate a solution of unknown concentration of HCl. A
      30.00 mL sample of the HCl solution required 24.21 mL of the NaOH solution for complete
      reaction. What is the molarity of the HCl solution? (see #1 for equation)

   4. A 34.53 mL sample of a solution of sulfuric acid, H 2SO4, reacts with 27.86 mL of 0.08964 M
      NaOH solution. Calculate the molarity and normality of the sulfuric acid solution. (see #2 for

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