Question

# 8. An aqueous solution of 0.043 M weak acid, HX, has a pH of 3.92. What is the pH of the solution if 0.021 mol of

KX is dissolved in one liter of the weak acid?

9. Calculate the pH of a solution prepared by mixing 100.0 mL of 1.20 M ethanolamine, C2H5ONH2 + with 50.0 mL of 1.0 M HCl. Ka for C2H5ONH3 + is 3.6 x 10-10 M.

10. A 0.1375 M solution of potassium hydroxide is used to titrate 35.00 mL of 0.257 M hydrobromic acid.

a) balance net ionic equation for the reaction that takes place during titration.

b) What volume of potassium hydroxide is required to reach the equivalence point?

c) What is the pH of the solution halfway to the equivalence point?

11. Consider the titration of benzoic acid (HBen) with potassium hydroxide. In an experiment, 25.00 mL of 0.175 M benzoic acid is titrated with 0.469 M KOH

a) balance net ionic equation for the reaction that takes place during titration.

b) What volume of potassium hydroxide is required to reach the equivalence point?

c) What is the pH of the solution halfway to the equivalence point?

d) What is the pH of the solution at the equivalence point?

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