AP Chem 8.7,8.8 pH and pKₐ …… and indicators!

Which of the following indicators is the best choice for this titration?

• Phenolphthalein

• Methyl orange

• Bromothymol blue

• Litmus

What type of titration curve is shown here?

• strong acid/weak base

• strong acid/strong base

• weak acid/weak base

• weak acid/strong base

At the equivalence point, the number of moles of titrant added is:

• equal to the number of moles of analyte

• twice the number of moles of analyte

• half the number of moles of analyte

• unrelated to the number of moles of analyte

The difference between the equivalence point and the end point is:

• The equivalence point is when the reaction is complete, while the end point is when the indicator changes color.

• The equivalence point is when the indicator changes color, while the end point is when the reaction is complete.

• Both terms mean the same thing in titration.

• The end point always occurs before the equivalence point.

Which of the following would not be considered a buffer solution?

• HNO₂ and KNO₂

• HC₂H₃O₂ and LiC₂H₃O₂

• HCl and KCl

What is a buffer?

• A buffer is a solution that produce hydrogen gas when reacted with a metal.

• A buffer is a solution that increases its pH rapidly when a strong acid is added.

• A buffer is a solution made only from strong acids and bases.

• A buffer is a solution made by combining a weak acid with its conjugate base. A buffer solution resists a change in pH upon the addition of a strong acid or base.

In the diagram above, identify the substance that will act as a buffer and neutralize the acidic (H⁺) ions.

• HF

• F^-

• Water

Which pair below could be used in a buffer solution?

• HCl and Cl⁻

• HNO₃ and NO₃⁻

• HC₂H₃O₂ and C₂H₃O₂⁻

Mixtures that would be considered buffers include which of the following?

• NaF and HF

• KCl and NaCl

• NaOH and KOH

• NaOH and HC.

A particular titration results in a solution at the equivalence point with a pH of 6.00. Which of the following would be a good choice for an indicator?

• thymol blue

• phenolphthalein

• bromcresol purple

• thymolphthalein