Titrations and Buffers

What is the pH at the equivalence point.

• The pH is ~4.5

• The pH is ~6.0

• The pH is ~8.5

• The pH is ~12.0

Which type of titration is shown by this titration curve?

• Titration of a strong acid with a strong base (SA/SB)

• Titration of a weak acid with a strong base (WA/SB)

• Titration of a strong base with a strong acid (SB/SA)

• Titration of a weak base with a strong acid (WA/SB)

CH₃COOH is titrated with NaOH. What is the pH at the equivalence point and what would be a good indicator to choose?

• pH = 5

  methyl red

• pH = 5

  phenolphthalein

• pH = 9

  methyl red

• pH = 9

  phenolphthalein

The pH of the solution at the buffer region (when equal concentrations of weak acid and conjugate base are present) is

• 2.86

• 4.75

• 8.77

• 12.01

If phenolphthalein turns pale pink, it indicates

• a solution with a pH less than 8.2

• a solution with a pH between 8.2 and 10.0

• a solution with a pH greater than 10.0

From the list of indicators shown, the one that is suitable for first equivalence point is

• bromothymol blue

• bromocresol green

• orange (IV)

• phenolphthalein

Which combination of solutions would produce the titration curve shown below?

• H₂SO₃ + KOH

• CH₃COOH + KOH

• Na₂CO₃ + HBr

• NH₃ + HBr

Which of the acids would have the weakest conjugate base?

• HCN
• H₂O
• CH₃OH
• HNO₃

In which of the following reactions does H₂PO₄^- act as an acid?

• H₃PO₄ + H₂O --> H₃O⁺ + H₂PO₄^-
• H₂PO₄^- + H₂O --> H₃O⁺ + HPO₄^2-
• H₂PO₄^- + H₂O --> H₃PO₄ + OH^-

• The ion cannot act as an acid

Which of the following is a conjugate acid/base pair?

• HCl/OCl^-
• H₂SO₄/SO₄^2-
• NH₄⁺/NH₃
• H₃O⁺/OH^-