AP Chemistry Topic 3.9

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

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

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

• 2.54
• 8.93
• 5.07
• 11.46

A weak acid, HF, is in solution with dissolved sodium fluoride, NaF. If HCl is added, which ion will react with the extra hydrogen ions from the HCl to keep the pH from changing?

• OH^-
• Na⁺
• F^-
• Na^-

The correct mathematical expression for finding the molar solubility (s) of Sn(OH)₂ is:

• 2s² = Ksp
• 2s³ = Ksp
• 4s³ = Ksp
• 8s³ = Ksp

The molar solubility of PbI₂ is 1.52 x 10^-3 M. Calculate the value of K_sp for PbI₂.

• 3.51 x 10^-9
• 1.40 x 10^-8
• 4.62 x 10^-6
• 1.52 x 10^-3

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

When the chemical reaction A + B ↔ C+ D is at equilibrium,

• both the forward and reverse reactions have stopped.
• the sum of the concentrations of A and B equals the sum of the concentrations of C and D.
• all four concentrations are equal.
• neither the forward nor the reverse reactions have stopped.

Tags

NGSS.HS-PS1-6

A substance that ionizes completely in solution is

• an insulator.
• a strong electrolyte. 
• a weak acid.
• a non-electrolyte.

Tags

NGSS.HS-PS1-1