Q1. Using the ICE table Calculate the pH of a solution that contains 0.0075 M Lactic acid and 0.085 M sodium lactate.
Q2. Use the Henderson equation to calculate the pH of the buffer solution in Question 1. Compare your answer to the one obtained from Q1.
Q3. What combination of substances will give a buffered solution that has a pH of about 8? Explain the reason for your choice. NH3 mixed with NH4Cl (Kb for NH3 = 1.8 x10-5) or C5H5N mixed with C5H5NHCl (Kb for C5H5N = 1.7x10-9)
Q4. Calculate the pH of a solution that is 0.210 M in Methylamine and 0.350 M in Methylamine hydrochloride.
Q5. Calculate the pH of a buffer prepared by mixing 50.0 mL of 1.00 M ammonia and 50.0 mL of 1.00 M ammonium nitrate (Remember to take dilution into account)
Q6. A solution contains 0.37 moles Formic acid (Ka= 1.77 x10-4) and 0.23 moles Sodium formate in 1.0 L of solution.
a) Calculate the pH of this solution
b) What will be the pH of the solution after 0.15 mol of NaOH(s) is added to the buffer in (a)
c) What will be the pH of the solution after 0.15 mol of HCl(g) is added to the buffer in (a)
Q7. 25.0 ml of 0.723 M HClO4 is titrated with 0.273 M KOH. Calculate the pH of the HCl solution at each of the following steps in the titration.
a) Initially before any KOH has been added.
b) 10.0 ml of KOH has been added
c) 25.0 ml of KOH has been added
d) At the equivalence point.
e) 70.0 ml of KOH has been added
Q8. Our blood buffer system includes a combination of H2CO3 with HCO3-. If Ka1 (H2CO3) = 4.3x10-7, what is the ratio of [HCO3-]/ [H2CO3] needed to maintain a pH of 7.40?
Q9. Consider the titration of 25.0 mL of 0.200 M NH3 (Kb = 1.8 x 10-5) with 0.200 M HCl. a) What is the initial pH of the NH3(aq)? b) What is the pH halfway to the equivalence point? c) What is the pH at the equivalence point? d) Sketch the titration curve. Label the point(s) where there is a A) a weak base B) weak acid C) Buffer D) Strong acid in excess,
Q10. The solubility of Ag2SO4 is found to be 4.5 g/L.
a) Calculate the molar solubility of Ag2SO4.
b) What is the Ksp for Ag2SO4?
Q11. What is the molar solubility of PbCl2 in 0.15 M HCl (Ksp for PbCl2 = 1.17 x 10-5)
Q12. The Ksp of Zn(OH)2 is 5.0 x 10-17. Calculate the concentration of the Zn2+ ions in a solution of Zn(OH)2 that has a pH of 9.62.
Q13. The Ksp of BaF2 is 2.45 x 10-5. a) Calculate its Molar solubility. b) What is the solubility in grams per liter.
Q14. Is CaF2 is more soluble in a solution of pH = 2 or pH = 9? Explain the reason for your answer clearly.