Chapter 10
Given the following balanced equation:
A+B⇌C+D
If the concentrations at equilibrium are [A] = 0.5 M, [B] = 0.5 M, [C] = 0.2 M, and [D] = 0.2 M, what is the equilibrium constant (K) for the reaction?
A) 0.8
B) 2.5
C) 1.0
D) 0.2
C) 1.0
This is the term used to describe the constant that compares the strength of a weak acid in solution.
A) Ka
B) Kb
C) pKa
D) pH
A) Ka
An atom of chlorine has an atomic number of 17 and a mass number of 35. How many neutrons does this atom have?
A) 17
B) 35
C) 18
D) 52
C) 18
How many milliliters are in 3.5 liters?
A) 0.35 mL
B) 35 mL
C) 350 mL
D) 3500 mL
D) 3500 mL
A chemist dilutes 100.0 mL of a 6.0 M solution of hydrochloric acid (HCl) to 250.0 mL. What is the molarity of the diluted solution?
A) 0.24 M
B) 1.5 M
C) 2.4 M
D) 3.0 M
C) 2.4 M
If the reaction quotient (Q) is greater than the equilibrium constant (K), which of the following will occur according to Le Chatelier’s principle?
A) The reaction will shift to the left to form more reactants.
B) The reaction will shift to the right to form more products.
C) The reaction is at equilibrium.
D) The reaction will stop.
A) The reaction will shift to the left to form more reactants.
Which of the following is a strong acid?
A) H₂SO₄
B) CH₃COOH
C) NH₃
D) H₂O
A) H₂SO₄ (Sulfuric acid)
What is the electron configuration for sulfur (S), atomic number 16?
A) 1s² 2s² 2p⁶ 3s² 3p⁶
B) 1s² 2s² 2p⁶ 3s² 3p⁴
C) 1s² 2s² 2p⁶ 3s² 3p⁶ 4s²
D) 1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹
B) 1s² 2s² 2p⁶ 3s² 3p⁴
What is the formula for the polyatomic ion nitrate?
A) NO₃⁻
B) NO₂⁻
C) SO₄²⁻
D) NH₄⁺
A) NO₃⁻
Which of the following is an example of a nonelectrolyte?
A) NaCl
B) KNO₃
C) C₆H₁₂O₆ (glucose)
D) NaOH
C) C₆H₁₂O₆ (glucose)
For the equilibrium reaction:
PCl3+Cl2⇌PCl5
If the equilibrium constant (K) is 2.0 at a certain temperature and the concentrations are [PCl₃] = 0.1 M, [Cl₂] = 0.2 M, and [PCl₅] = 0.3 M, what is the value of the reaction quotient (Q)?
A) Q = 0.2
B) Q = 1.2
C) Q =15
D) Q = 0.9
C) Q =15
If a solution has a pH of 3, the concentration of [H₃O⁺] in the solution is:
A) 1 × 10⁻³ M
B) 1 × 10⁻⁶ M
C) 1 × 10⁻⁹ M
D) 1 × 10⁻¹⁰ M
A) 1 × 10⁻³ M
Which of the following elements is a metalloid?
A) Sodium (Na)
B) Silicon (Si)
C) Oxygen (O)
D) Chlorine (Cl)
B) Silicon (Si)
What is the balanced equation for the combustion of methane (CH₄)?
A) CH₄ + 2O₂ → CO₂ + 2H₂O
B) CH₄ + O₂ → CO₂ + 2H₂O
C) 2CH₄ + 2O₂ → 2CO₂ + 4H₂O
D) CH₄ + O₂ → 2CO₂ + 4H₂O
A) CH₄ + 2O₂ → CO₂ + 2H₂O
In a reaction where 10.0 grams of hydrogen gas (H₂) react with 40.0 grams of oxygen gas (O₂) to form water (H₂O), what is the limiting reactant? (Molar masses: H₂ = 2.0 g/mol, O₂ = 32.0 g/mol)
A) Hydrogen gas (H₂)
B) Oxygen gas (O₂)
C) Both reactants are limiting
D) There is no limiting reactant
B) Oxygen gas (O₂)
Which of the following is an effect of increasing the temperature on an exothermic reaction at equilibrium, according to Le Chatelier’s principle?
A) The equilibrium will shift to the right to produce more products.
B) The equilibrium will shift to the left to absorb the added heat.
C) The equilibrium will not change.
D) The reaction will stop.
B) The equilibrium will shift to the left to absorb the added heat.
What is the conjugate base of HSO₄⁻ in the reaction HSO₄⁻ ⇌ H⁺ + SO₄²⁻?
A) H₂SO₄
B) SO₄²⁻
C) HSO₄
D) OH⁻
B) SO₄²⁻
Which of the following is an example of a homogeneous mixture?
A) Salad dressing
B) Air
C) Soil
D) Oil and water
B) Air
How many grams are in 0.5 moles of sodium chloride (NaCl)? (Molar mass of NaCl = 58.44 g/mol)
A) 29.22 grams
B) 58.44 grams
C) 116.88 grams
D) 29.44 grams
A) 29.22 grams
How many milliliters of a 6.0 M NaOH solution are required to prepare 500.0 mL of a 2.0 M NaOH solution?
166.67 mL
For the reaction
CH₃COOH+H₂O⇌CH₃COO−
The equilibrium constant (Ka) for acetic acid is 1.8 × 10⁻⁵. If the concentration of CH₃COOH is 0.1 M and the concentration of H₃O⁺ at equilibrium is 1.3 × 10⁻³ M, what is the concentration of CH₃COO⁻ at equilibrium?
A) 1.3 × 10⁻⁶ M
B) 1.3 × 10⁻⁴ M
C) 1.3 × 10⁻³ M
D) 1.0 × 10⁻² M
C) 1.3 × 10⁻³ M
What is the pH of a 0.025 M solution of HNO₃, a strong acid?
A) 1.60
B) 2.60
C) 4.60
D) 5.60
A) 1.60
If an element has two isotopes, one with a mass of 10 amu and an abundance of 75%, and another with a mass of 12 amu and an abundance of 25%, what is the average atomic mass of the element?
A) 10.5 amu
B) 11.0 amu
C) 11.5 amu
D) 12.0 amu
A) 10.5 amu
How many atoms of oxygen (O) are present in 25.0 grams of water (H₂O)?
8.36×10^23
A 1.5 L container holds 0.4 moles of a gas at a temperature of 350 K. The gas is compressed to a final volume of 0.5 L. If the gas's pressure increases from 2.0 atm to 5.0 atm during the compression, calculate the final temperature of the gas.
291.67 K