Acid Base Equilibrium

Which is the weakest acid?

• HF
• HNO₂
• CH₃COOH
• HClO

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

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

Calculate the pH of a 0.47M NH₃ (K_b = 1.8 x 10^-5) solution.

• 2.54
• 8.93
• 5.07
• 11.46

The pH of a solution at 25^ₒC in which [OH-] = 3.9 x 10^-5M is:

• 4.41
• 3.90
• 9.59
• 4.80

Calculate the [H⁺] in a solution that has a pH of 2.73.

• 5.4 x 10^-12 M
• 1.9 x 10^-3 M
• 2.7 M
• 11.3 M

The pH at the equivalence point of the titration of a strong acid with a strong base is:

• 3.9
• 4.5
• 7.0
• 8.2

Which of the following is the conjugate acid of HCO₃^-1?

• H₂CO₃
• CO₃^-2
• H₂CO_3^-1
• CO₃^-1

Phenol, C₆H₅OH, has a K_a =1.0 x 10^-10. What is the pH of a 0.010 M solution of phenol?

• between 3-7

• 10

• 2

• between 7-10

• 7

Calculate the [H⁺] in a solution that has a pH of 2.73.

• 5.4 x 10^-12 M
• 1.9 x 10^-3 M
• 2.7 M
• 11.3 M

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.