Chemistry Practice Exam 3
21 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the concentration of the original sulfuric acid solution if 34.62 mL of 0.1510 M NaOH is needed to neutralize 50.0 mL of the solution?

  • 0.209 M (correct)
  • 0.0523 M
  • 0.0229 M
  • 0.218 M

Which species acts as the oxidizing agent in the reaction: 5Fe2+(aq) + MnO−4(aq) + 8H+(aq) → 5Fe3+(aq) + Mn2+(aq) + 4H2O(l)?

  • Fe3+
  • Fe2+
  • MnO−4 (correct)
  • H+

At 1000.0 K, if Kp = 29.1, what is the value of Kc at the same temperature?

  • 5.39
  • 0.0687 (correct)
  • 0.0344
  • 0.185

Which disturbance will NOT cause a shift to the right in the equilibrium system?

<p>The volume decreases. (A)</p> Signup and view all the answers

What is the molar concentration of a hydrochloric acid solution if 46.33 mL of 0.243 M NaOH neutralizes 10.00 mL of it?

<p>1.13 M (B)</p> Signup and view all the answers

Which statement is true regarding the reaction with Kp = 0.0017 at 2300 K, where the partial pressures are at 0.660 atm and PNO = 0.0272 atm?

<p>Q &gt; K, so the reaction will consume products to make more reactants. (D)</p> Signup and view all the answers

What is the equilibrium concentration of NO for the reaction N2(g) + O2(g) ⇌ 2NO(g) when starting with 0.040 M of both reactants?

<p>0.0096 M (C)</p> Signup and view all the answers

What is the correct relationship between Kp and Kc for Kp = 1.61 × 10−5 at 1400.0 K?

<p>1.40 × 10−7 (B)</p> Signup and view all the answers

Which change will shift the equilibrium position to favor the formation of more products for the reaction 2NOBr(g) ⇌ 2NO(g) + Br2(g)?

<p>Remove Br2. (A)</p> Signup and view all the answers

Which statement regarding the equilibrium constant is FALSE?

<p>When K = 1, forward and reverse rate constants differ. (C)</p> Signup and view all the answers

What is the calculated volume occupied by 25.2 g of CO2 at 0.84 atm and 25°C?

<p>1.34 L (C)</p> Signup and view all the answers

In which of the following compounds is the oxidation number of sulfur (S) equal to +4?

<p>SO2 (A)</p> Signup and view all the answers

Which equilibrium expression corresponds to the reaction A ⇌ B?

<p>[B]/[A] (A)</p> Signup and view all the answers

How many grams of iron(III) hydroxide will precipitate if 50.0 mL of 0.500 M sodium hydroxide is added to 75.0 mL of 0.200 M iron(III) nitrate?

<p>0.891 g (B)</p> Signup and view all the answers

What volume of a 0.452 M NaOH solution is needed to neutralize 85 mL of a 0.176 M solution of H2SO4?

<p>66.2 mL (A)</p> Signup and view all the answers

In the smelting of iron from iron oxide, which species is oxidized?

<p>Fe in Fe2O3 (D)</p> Signup and view all the answers

What will be the volume of the balloon at an altitude where the pressure is 530 torr if it was initially 3.00 L at 765 torr?

<p>4.33 L (C)</p> Signup and view all the answers

How many grams of helium does a cylinder contain if the pressure gauge shows 1275 psi at a temperature of 25.00°C in a volume of 10.0 L?

<p>521 g (A)</p> Signup and view all the answers

What is the mole fraction of O2 in a gas mixture with a total pressure of 750 torr when the partial pressure of O2 is 125 torr?

<p>0.200 (C)</p> Signup and view all the answers

Calculate the equilibrium constant Kc for the reaction with the following equilibrium concentrations: [CH4] = 0.3322 M, [H2S] = 0.6644 M, [CS2] = 0.0678 M, and [H2] = 0.2712 M.

<p>0.167 (D)</p> Signup and view all the answers

Calculate the theoretical value of the equilibrium constant for the reactions involving nitrogen and oxygen at high temperatures given appropriate K values.

<p>1.2 × 10⁶ (D)</p> Signup and view all the answers

Flashcards

Iron(III) hydroxide precipitation

The amount of iron(III) hydroxide that precipitates when sodium hydroxide is added to iron(III) nitrate.

Neutralization of H2SO4 with NaOH

The volume of 0.452 M NaOH required to neutralize 85 mL of 0.176 M H2SO4.

Oxidation in iron smelting

The substance oxidized in the reaction to produce iron from iron oxide.

Balloon volume change with pressure

The new volume of a helium balloon at a different pressure, assuming constant temperature.

Signup and view all the flashcards

Helium in a cylinder (grams)

Calculating the mass of helium contained in a cylinder with known pressure and temperature.

Signup and view all the flashcards

Mole fraction of O2

Percentage of oxygen in a gas mixture based on partial pressures.

Signup and view all the flashcards

Equilibrium expression calculation

Formula to determine the equilibrium constant value (Kc) from various reaction components' concentrations.

Signup and view all the flashcards

Equilibrium constant calculation (K2)

Calculating the theoretical equilibrium constant for a compound reaction using known equilibrium constants for sub-reactions.

Signup and view all the flashcards

Equilibrium Constant (Kp)

Kp represents the ratio of product partial pressures to reactant partial pressures at equilibrium, for a gaseous reaction.

Signup and view all the flashcards

Reaction Quotient (Q)

Q is similar to Kp, but calculates the ratio of pressures at any given time in a reaction, not just equilibrium.

Signup and view all the flashcards

Equilibrium Concentration of NO

The concentration of NO at equilibrium when N2(g) + O2(g) ⇌ 2NO(g).

Signup and view all the flashcards

Relationship between Kp and Kc

Kp and Kc are related by the equation Kp = Kc(RT)^Δn, where R is the ideal gas constant, T is temperature in Kelvin, and Δn is the difference in the moles of gaseous products and reactants.

Signup and view all the flashcards

Factors Affecting Equilibrium Position

Changes in pressure, temperature, and concentration can shift the equilibrium of a reaction towards products or reactants, according to Le Chatelier's principle.

Signup and view all the flashcards

Large K value

When the equilibrium constant (K) is much greater than 1, products are favored at equilibrium.

Signup and view all the flashcards

Ideal Gas Law Equation

The Ideal Gas Law relates the pressure, volume, temperature, and number of moles of a gas. PV = nRT.

Signup and view all the flashcards

Equilibrium constant affects reaction speed

The size of the equilibrium constant (K) does NOT directly affect how fast a reaction reaches equilibrium. Rate constants (k) control reaction speed.

Signup and view all the flashcards

Oxidizing agent in 5Fe2+ + MnO4- + 8H+ → 5Fe3+ + Mn2+ + 4H2O

The oxidizing agent is the substance that gains electrons. In this reaction, MnO4- gains electrons, so it is the oxidizing agent.

Signup and view all the flashcards

Equilibrium shift that NOT affect a chemical reaction. (not disturbing equilibrium )

If you change the volume of a reaction at equilibrium, it will cause the reaction to shift to either the reactants side or the products side to compensate for the change. In this particular case, decreasing or increasing volume does not shift the equilibrium, thus not disturbing the reaction.

Signup and view all the flashcards

Molarity of H2SO4 for neutralization

34.62 mL of 0.1510 M NaOH neutralizes 50.0 mL of H2SO4. The concentration of the H2SO4 solution is 0.0523 M.

Signup and view all the flashcards

Calculating HCl concentration from neutralization

For 46.33 mL of 0.243 M NaOH neutralizing 10.00 mL of HCl, the molar concentration of the acid is 1.13 M;

Signup and view all the flashcards

Study Notes

Practice Exam 3 - Chemistry

  • Problem 1: Determine the grams of iron(III) hydroxide precipitate formed when 50.0 mL of 0.500 M sodium hydroxide is mixed with 75.0 mL of 0.200 M iron(III) nitrate. The answer is 1.60 g.

  • Problem 2: Calculate the volume of 0.452 M NaOH solution needed to neutralize 85 mL of 0.176 M H₂SO₄. The answer is 66.2 mL.

  • Problem 3: Identify the oxidized species in the reaction Fe₂O₃(s) + 3 CO(g) → 2Fe(s) + 3 CO₂(g). The answer is C in CO.

  • Problem 4: A balloon filled with 3.00 L of helium at 765 torr changes volume at a different altitude where the pressure is 530 torr (temperature constant). Calculate the new volume. The answer is 4.33 L.

  • Problem 5: A helium-filled cylinder at 25.00°C and 1275 psi has a volume of 10.0 L. Calculate the grams of helium in the cylinder. The answer is 521 g.

  • Problem 6: A gas mixture has a total pressure of 750 torr, and the partial pressure of O₂ is 125 torr. Calculate the mole fraction of O₂. The answer is 0.167.

  • Problem 7: Write the equilibrium expression for the reaction 2 NO(g) ⇌ N₂(g) + O₂(g). The answer is K = [N₂][O₂]/[NO]².

  • Problem 8: Determine the equilibrium constant (Kc) for the reaction CH₄(g) + 2 H₂S(g) ⇌ CS₂(g) + 4 H₂(g). Given equilibrium concentrations, calculate Kc. The answer is 2.50 x 10⁻³.

  • Problem 9: Given equilibrium constants (K₁) and (K₂) for N₂O(g) ⇌ 2 NO₂(g) and N₂(g) + O₂(g) ⇌ NO₂(g), respectively, Calculate the theoretical equilibrium constant for N₂(g) + 2O₂(g) ⇌ N₂O(g). The answer is 1.6 x 10⁻¹¹.

  • Problem 10: Given the equilibrium N₂(g) + O₂(g) ⇌ 2 NO(g) and partial pressures, determine if the reaction will continue to make more products or reactants. The answer is Q<K, so the reaction will continue to make more products.

  • Problem 11: Given the reaction N₂(g) + O₂(g) ⇌ 2NO(g) and initial concentrations, calculate the equilibrium concentration of NO. The answer is 9.6 x 10⁻³ M.

  • Problem 12: Given CO(g) + 3 H₂(g) ⇌ CH₄(g) + H₂O(g) and Kp, calculate Kc. The answer is 1.22 × 10⁻⁹.

  • Problem 13: Identify the change that will shift the position of equilibrium for the reaction 2NOBr(g) ⇌ 2NO(g) + Br₂(g) to favor product formation. The answer is lower the temperature.

  • Problem 14: State the false statement about equilibrium constants. The answer is When K >> 1, the products and reactants come to equilibrium rapidly.

  • Problem 15: Write the equilibrium expression for the reaction 2 NO(g) ⇌ N₂(g) + O₂(g). The answer is K =[N₂][O₂]/[NO]²

  • Problem 16: Calculate the volume occupied by 25.2 g of CO₂ at 0.84 atm and 25°C. The answer is 16.9 L.

  • Problem 17: Identify the compound where the oxidation number of sulfur is +4. The answer is Na₂SO₃.

  • Problem 18: For the equilibrium 2 HI(g) ⇌ H₂(g) + I₂(g), given Kp at a certain temperature, calculate Kc. The answer is 0.0687.

  • Problem 19: Identify the oxidizing agent in the reaction 5Fe²⁺(aq) + MnO₄⁻(aq) + 8H⁺(aq) → 5Fe³⁺(aq) + Mn²⁺(aq) + 4H₂O(l). The answer is MnO₄⁻.

  • Problem 20: Which disturbance in the equilibrium CH₄(g) + H₂O(g) ⇌ CO(g) + 3 H₂(g) does not cause the system to shift to the right? The correct answer is the increase in the partial pressure of CH₄.

  • Problem 21: Calculate the concentration of H₂SO₄ if 50.0 mL was neutralized by 34.62 mL of 0.1510 M NaOH. The answer is 0.0523 M.

  • Problem 22: Calculate the molar concentration of the hydrochloric acid given a standard NaOH solution and volumes. The answer is 1.13 M.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Related Documents

F21 Practice Exam 3 (PDF)

Description

Test your knowledge with this Chemistry Practice Exam 3. This quiz covers important concepts such as stoichiometry, gas laws, and acid-base neutralization. Solve problems related to chemical reactions and various calculations in chemistry to ensure you have a solid understanding of the material.

More Like This

Gas Laws and Stoichiometry Quiz
3 questions
Stoichiometry and Gas Laws
10 questions
Use Quizgecko on...
Browser
Browser