Acid/Base Titrations

What is the main purpose of acid-base titrations?

• To test if reactants react.

• To calculate the concentration of unknown analyte.

• To calculate the concentration of known analyte.

• To test quality of reactants.

What is the role of an indicator in a reaction?

• To help reactants react successfully.

• To bind to the analyte to form a products.

• To show when the reaction has reached or past the equivalence point.

• To provide a surface for the reaction to occur.

What is an equivalence point?

• It is the point when enough analyte has been added.

• It is the point when the amount of added titrant is equal to the amount of analyte in the solution.

• It is the point when the volume of titrant is equivalent the volume of analyte.

• It is the point when the concentration of titrant added is equivalent to the volume of analyte.

what is the reading on this burette?

• 4.40mL
• 3.50mL
• 3.60mL
• 4.50mL

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

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

Ascorbic acid, H₂C₆H₆O₆(s), is a diprotic acid with K₁ = 7.9 × 10^–5 and K₂ = 1.6 × 10^–12. In a 0.005 M aqueous solution of ascorbic acid, which of the following species is present in the lowest concentration?

• H₃O⁺(aq)

• H₂C₆H₆O₆(aq)

• HC₆H₆O₆^-(aq)

• C₆H₆O₆^2-(aq)

Tags

NGSS.HS-PS1-7

In the titration of a weak acid of unknown concentration with a standard solution of a strong base, a pH meter was used to follow the progress of the titration. Which of the following is true for this experiment?

• The [H⁺] at the equivalence point equals the ionization constant of the acid.

• The pH at the equivalence point depends on the indicator used.

• The graph of pH versus volume of base added rises gradually at first and then much more rapidly.

• The graph of pH versus volume of base added shows no sharp rise.

Which of the following best approximates the K_a value for this weak acid?

• 1 x 10^–4

• 1 x 10^–5

• 5x 10^–6

• 5 x 10^–7

Which point on the titration curve corresponds to the point at which the moles of the added strong base are equal to the moles of the weak acid initially present?

• Q

• R

• S

• T

At point P in the titration, which of the following species has the highest concentration?

• HA

• A^–

• H₃O⁺

• OH^–

Tags

NGSS.HS-PS1-3