Problem Set #12 – Mixed Solutions and Buffers 1. Explain what happens to (a) the concentration of H 3 O + ions in an acetic acid solution when solid sodium acetate is added; (b) the percentage deprotonation of benzoic acid in a benzoic acid solution when hydrochloric acid is added; (c) the pH of the solution when solid ammonium chloride is added to aqueous ammonia. 2. A solution of equal concentrations of lactic acid and sodium lactate was found to have pH = 3.08. (a) What are the values of pK a and K a of lactic acid? (b) What would the pH be if the acid had twice the concentration of the salt? 3. Determine the pH and pOH of a solution that is (a) 0.50 M NaHSO 4 (aq) and 0.25 M Na 2 SO 4 (aq); (b) 0.50 M NaHSO 4 (aq) and 0.10 M Na 2 SO 4 (aq); (c) 0.50 M NaHSO 4 (aq) and 0.50 M Na 2 SO 4 (aq). 4. The pH of 0.40 M HF(aq) is 1.93. Calculate the change in pH when 0.356 g of sodium fluoride is added to 50.0 mL of the solution. Ignore any change in volume. 5.
This is the end of the preview. Sign up
access the rest of the document.
This note was uploaded on 04/18/2011 for the course CH 302 taught by Professor Holcombe during the Spring '07 term at University of Texas at Austin.