Do Now - AP - Acid Base Titrations

A 50.0 mL sample of an acid, HA, of unknown molarity is titrated, and the pH is measured and graphed as 0.100 M is NaOH added.

Which of the following is the best particulate representation of the species (other than H₂O) that are present in significant concentrations in the solution at point U in the titration?

• 
• 
• 
• 

Which point on the titration curve corresponds to the point where the moles of the added strong base are equal to the moles of the weak acid?

• Q

• R

• S

• T

Which type of titration is shown by this titration curve?

• Titration of a strong acid by a strong base 
• Titration of a weak acid by a strong base 
• Titration of a strong base by a strong acid 
• Titration of a weak base by a strong acid

The reaction of perchloric acid (HClO₄) with lithium hydroxide (KOH) is described by the equation

HClO₄ + KOH → KClO₄ + H₂O

Suppose 100 mL of perchloric acid is neutralized by exactly 50.0 mL of 1.0 M of Potassium hydroxide. What is the concentration of the perchloric acid?

• 0.5M

• 50M

• 2.0M

• 1.0M

A 50.0 mL sample of an acid, HA, of unknown molarity is titrated, and the pH is measured and graphed as 0.100 M of NaOH is added.

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

• HA

• A^-

• H₃O⁺

• OH^-

An unknown acid is dissolved in 25 mL of water and titrated with 0.100 M NaOH. The results are shown in the titration curve above. Which of the following could be the unknown acid?

• Fluoroacetic acid, pKa = 2.6

• Glycolic acid, pKa = 3.8

• Propanoic acid, pKa = 4.9

• Hypochlorous acid, pKa = 7.5

• Boric acid, pKa = 9.3

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

B(aq) + HCl(aq) ↔ HB⁺(aq) + Cl^-(aq)

The graph above shows the titration curve for an aqueous solution of a weak base, B, with HCl as the titrant. Based on the graph, which of the following best estimates the pK_a of HB⁺?

• 12.0

• 9.2

• 5.5

• 1.8

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 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.

Which curve is produced by the addition of a strong acid to a strong base?

• A

• B

• C

• D

Tags

types of titrations