ksp and buffers

Which of the following shows the correct dissolution reaction for BaCl₂?

• Ba ²⁺(aq) + Cl₂^-(aq) -> BaCl₂(s)
• BaCl₂(aq) -> Ba ²⁺(aq) + 2Cl^-(aq)
•  BaCl₂(s) -> Ba ²⁺(aq) + 2Cl^-(aq)
• Ba ²⁺(aq) + 2Cl^-(aq) -> BaCl₂(s)

Tags

NGSS.HS-PS1-2

An unknown salt, M₂Z, has a K_sp of 3.3 x 10^-9. Calculate the solubility in mol/L of M₂Z.

• 2.9 x 10^-4 M

• 5.7 x 10^-4 M

• 9.4 x 10^-4 M

• 3.7 x 10^-4 M

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

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

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^-

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

Which is the weakest acid?

• HF
• HNO₂
• CH₃COOH
• HClO