pb 13 - with 34.20 mL of 0.0695 M HCl(aq). What is the...

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Problem Set #13 – Titrations 1. Sketch the pH curve for the titration of 20.0 mL of 0.10 M HCl(aq) with 0.20 M KOH(aq). Mark the initial pH and the pH at the stoichiometric point. 2. Calculate the volume of 0.150 M HCl(aq) required to neutralize (a) one-half and (b) all the hydroxide ions in 25.0 mL of 0.110 M NaOH(aq). (c) What is the molarity of Na + ions at the stoichiometric point? (d) Calculate the pH of the solution after the addition of 20.0 mL of 0.150 M HCl(aq) to 25.0 ML of 0.110 M NaOH(aq). 3. Suppose that 4.25 g of an unknown monoprotic weak acid, HA, is dissolved in water. Titration of the solution with 0.350 M NaOH(aq) required 52.0 mL to reach the stoichiometric point. After the addition of 26.0 mL, the pH of the solution was found to be 3.82. (a) What is the molar mass of the acid? (b) What is the value of pK a for the acid? 4. Suppose that 1.436 g of impure sodium hydroxide is dissolved in 300. mL of aqueous solution and that 25.00 mL of this solution is titrated to the stoichiometric point
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Unformatted text preview: with 34.20 mL of 0.0695 M HCl(aq). What is the percentage purity of the original sample? 5. Calculate the pH at each stage in the titration for the addition of 0.150 M HCl(aq) to 25.0 mL of 0.110 M NaOH(aq) (a) initially; (b) after the addition of 5.0 mL of acid; (c) after the addition of a further 5.0 mL; (d) at the stoichiometric point; (e) after the addition of 5.0 mL of acid beyond the stoichiometric point; (f) after the addition of 10.0 mL of acid beyond the stoichiometric point. 6. Suppose that 25.0 mL of 0.10 M CH 3 COOH(aq) is titrated with 0.10 M NaOH(Aq). (a) What is the initial pH of the 0.10 M CH 3 COOH(aq) solution? (b) What is the pH after the addition of 10.0 mL of 0.10 M NaOH(aq)? (c) What volume of 0.10 M NaOH(aq) is required to reach halfway to the stoichiometric point? (d) Calculate the pH at that halfway point. (e) What volume of 0.10 M NaOH(aq) is required to reach the stoichiometric point? (f) Calculate the pH at the stoichiometric point....
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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.

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