Acid-Base Titrations Problems

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.

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

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

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

• Methyl orange (pH range of color change is 3.2 - 4.4)

• Methyl red (pH range of color change is 4.8 - 6.0)

• Bromothymol blue (pH range of color change is 6.1 - 7.6)

• Phenolphthalein (pH range of color change is 8.2 - 10.0)

If the Erlenmeyer flask contains acidic solution and a few drops of phenolphthalein, its color will be

• pink

• blue

• red

• colorless

What color is phenolphthalein in a base?

• colorless

• pink

• blue

• green

What term describes the change in color of the indicator during a titration?

• colorizing

• endpoint

• equivalence point

• endgame

Acids react with

• water to produce bases and salts
• salts to produce bases and water
• neither bases, salts nor water
• bases to produce salts and water

A student used a 0.125 M of sodium hydroxide solution in a titration experiment. The initial reading on the buret was 0.45 mL. After the titration, the buret reading was 14.98 mL. How many moles of sodium hydroxide was used?

• 1.82 moles

• 1.82 x 10^-3 moles

• 8.34 x 10^-3 moles

• 8.6 moles