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Which beaker represents a buffered solution?

You dissolve 1.45 grams of unknown diprotic acid in 200.0 mL of water. This solution is neutralized by 5.00 mL of 1.00M NaOH solution. What is the molar mass of the unknown acid? A: HI B: HNO 2 C: NaOH D: Ba(OH) 2 E: NH 4 Cl F: C 2 H 5 NH 2 Compare pH of

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Which beaker represents a buffered solution?

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  1. You dissolve 1.45 grams of unknown diprotic acid in 200.0 mL of water. This solution is neutralized by 5.00 mL of 1.00M NaOH solution. What is the molar mass of the unknown acid? • A: HI B: HNO2 C: NaOH • D: Ba(OH)2 E: NH4Cl F: C2H5NH2 • Compare pH of • A ___ B B ___ E C___F • C ___ D E ___ F • Percent ionization in A ___ C • (Use >,<,=, or need more information)

  2. An acid is titrated with NaOH. The ff beakers are illustrations of the contents of the beaker at various times during the titration. These are represented out of order. Counter-ions and water are omitted for clarity. • Is the acid weak or strong? How can you tell? • Arrange in order of what the contents will look like as the titration progresses. • For which beaker is pH=pKa? • Which represents equivalence point? • For which beaker would the Ka value not necessary to determine the pH?

  3. Which beaker represents a buffered solution?

  4. #51. Consider the titration of generic weak acid HA with a strong base. • On the curve, indicate the points: • Stoichiometric (equivalence) point • The region with maximum buffering • pH=pKa • pH depends only on [HA] • pH depends only on [A-] • pH depends only on the amount of excess strong base added

  5. #124 • Which pH curve corresponds to the weakest acid? • Strongest acid? Which point in the curve would you examine to see if this is strong acid or weak acid? (assuming you did not know the initial concentration) • Which acid corresponds to an acid with Ka= 1 x 10-6?

  6. #124

  7. #143 When a diprotic acid, H2A, is titrated with NaOH, the protons on the diprotic acid are generally removed one at a time, resulting in a pH curve that has the following generic shape: • If the first equiv pt occurs at 100mL NaOH, what volume of NaOH added corresponds to the second equivalence pt? • For the ff volumes of NaOH added, list the major species after NaOH reacts completely:0,1-100,100,100-200,200mL

  8. #143

  9. #144. Titration of Na2CO3 with HCl a) Identify major species at points A to F b) Calculate pH at the halfway pts to equiv B & D c) If a mixture of NaHCO3 and Na2CO3 was titrated, what would be the relative sizes of V1&V2? d) If a mixture of NaOH and Na2CO3 was titrated, what would be the relative sizes of V1 and V2? e) Sample contains mixture of NaHCO3 and Na2CO3. When this sample was titrated with 0.1MHCl, it took 18.9mL to reach the 1st equiv pt and an additional 36.7mL to reach the 2nd equiv pt. What is the composition in mass % of the sample?

  10. #144

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