CHM 152 Section B

Write the formula of the conjugate acid of the Brønsted-Lowry base, (CH₃)₃N

(CH₃)₃NH⁺

An evacuated reaction vessel is filled with 3.60 atm of NOCl. When the system reaches equilibrium according to the reaction below, there are 0.160 atm of NOCl. What is Kp for this reaction? 2 NO (g) + Cl₂ (g) ⇌ 2 NOCl (g)

0.00126

The Kp for the reaction A (g) ⇌ 2 B (g) is 0.0450. What is Kp for the reaction 2 A (g) ⇌ 4 B (g)?

0.00203 Equilibrium constants are the products divided by the reactants. Coefficients become exponents. Because of this, multiplying the coefficients by 2 results in an exponent of 2. (0.0450)/2=0.00203

An unknown weak acid with a concentration of 0.090 M has a pH of 1.80. What is the Ka of the weak acid?

0.0034

An equilibrium is established for the reaction 2 CO(g) + MoO₂(s) ⇌ 2 CO₂(g) + Mo(s). Use the expression for Kp from part a. If at equilibrium the partial pressure of carbon monoxide is 5.21 atm and the partial pressure of the carbon dioxide is 0.643 atm, then what is the value of Kp?

0.0152

An equilibrium is established for the reaction 2 CO(g) + MoO₂(s) ⇌ 2 CO₂(g) + Mo(s). Use the expression for Kp from part a. A system which is not necessarily at equilibrium has a partial pressure of carbon monoxide of 1.67 atm and a partial pressure of carbon dioxide of 0.306 atm. What is the value of Q, the reaction quotient?

0.0336

A solution is made initially with 0.200 M HIO₃ (Kc = 0.170). Once the equilibrium below is established, what is the equilibrium concentration of H⁺ ions? HIO₃ (aq) ⇌ H+ (aq) + IO₃⁻ (aq)

0.118 M

A student initially adds 1.00 mol of A to an empty 1.0 L flask. After 10 minutes, there are 0.83 mol of A left. What is the reaction quotient? Equation: A(aq) → 2 B(aq)

0.14

What is the percent ionization of H₂NNH₂ in a solution with a concentration of a 0.520 M? (Kb = 1.3 × 10⁻⁶)

0.16 %

An evacuated reaction vessel is filled with 0.800 atm of N₂ and 1.681 atm of Br₂. When equilibrium is established according to the reaction below, there are 1.425 atm of Br₂ remaining in the vessel. What is the equilibrium partial pressure of NBr₃? 2 NBr₃ (g) ⇌ N₂ (g) + 3 Br₂ (g)

0.171 atm

If the equilibrium constant of a given reaction is 2.54, what is the equilibrium constant of its reverse reaction?

0.394 The following solution may contain one or more values that are different from the problem provided to you, however, the steps to solve the problem are the same. If a reaction is reversed, the equilibrium constant expression is inverted.12.54=0.394

The pOH of a 0.300 M solution of NaOH is

0.523

A reaction vessel initially contains only 3.5 atm of N₂O₄. When the system reaches equilibrium according to the reaction below, there is 1.7 atm of NO₂ in the vessel. Determine the Kp for the following reaction: 2 NO₂ (g) ⇌ N₂O₄ (g)

0.92 The equilibrium pressure of N2O4N2O4 can be found by setting up an ICE table. N2O4NO2 Initial 3.5 0 Change −x +2x Equilibrium 3.5−x 1.7 Solve for x. 0+2x=1.70 x=0.85 Then find the equilibrium pressure for N2O4N2O4.3.5−0.85=2.653.5−0.85=2.65 Next, set up the equilibrium constant for this reaction and plug in the pressures. The equilibrium constant is calculated by dividing the partial pressures of the products by the partial pressures of the reactants.Kp=PN2O4/(PNO2)2=2.65/(1.7)2=0.92

The pOH of 0.0200 M solution of Sr(OH)₂ is

1.398

If Kc = 0.0084 for the reaction below at 298.0 K, then what is the value of Kp? (R = 0.0821 L･atm/mol･K.) 3 A (g) + B (g) ⇌ C (g) + D (g)

1.4 × 10⁻⁵ Kp can be calculated using the given Kc, the change in the moles of gas, and temperature. Kp=Kc(RT)Δn=()ΔKp=0.0084(0.0821∗298.0K)−2=0.0084(0.0821∗298.0)−2Kp=1.4×10−5

An unknown weak acid with a concentration of 0.440 M has a pH of 5.600. What is the Ka of the weak acid?

1.43 × 10⁻¹¹

What is the pH of a 0.400 M solution of HF (Ka = 6.8 × 10⁻⁴)?

1.79

Consider the following reactions: A ⇌ B, K₁=3.76 A ⇌ C, K₂=2.00 What is K for the reaction C ⇌ B?

1.88 The following solution may contain one or more values that are different from the problem provided to you, however, the steps to solve the problem are the same. When there are multiple equations, K=K1×K2=1×2. Add the equations together to achieve the target equation. When you reverse the equation, you have to "flip" the K. A⇌B3.76⇌B3.76C⇌A12.00---------------------C⇌12.00_C⇌B1.88

What is the pH of a 0.0820 M solution of methylamine (CH₃NH₂, Kb = 4.4 × 10⁻⁴)?

11.78

The pH of a 0.0040 M solution of Ca(OH)₂ is

11.90

What is Kb for the conjugate base of HCN (Ka = 4.9 × 10⁻¹⁰)?

2.0 × 10⁻⁵

The equilibrium constant for the reaction 2 HF (g) ⇌ H₂ (g) + F₂ (g) is 0.210 at a particular temperature. What is the equilibrium constant for the equation ½ H₂ (g) + ½ F₂ (g) ⇌ HF (g)?

2.18 The following solution may contain one or more values that are different from the problem provided to you, however, the steps to solve the problem are the same. If a reaction is reversed, the equilibrium constant expression is inverted. Equilibrium constants are the products divided by the reactants. Coefficients become exponents. Because of this, multiplying the coefficients by 1/2 results in an exponent of 1/2.1(0.210)1/2=2.18

What is Ka for the conjugate acid of CH₃NH₂ (Kb = 4.4 × 10⁻⁴)?

2.3 × 10⁻¹¹

The pH of a 0.0040 M solution of HNO₃ is

2.40

If Kp = 947 for the reaction below at 310.0 K, then what is the value of Kc? Note Kc is sometimes called K. (R = 0.0821 L･atm/mol･K.) 2 A (g) + B (s) ⇌ 2 C (s) + D (g)

2.41 × 10⁴ Kc can be calculated using the given Kp, the change in the moles of gas, and temperature. Kp=Kc(RT)Δn=()Δ947=Kc(0.0821∗310.0K)−1947=(0.0821∗310.0)−1947(0.0821∗310.0K)−1=Kc947(0.0821∗310.0)−1=2.41×104=Kc

What is the percent ionization in a 0.300 M solution of formic acid (HCOOH) (Ka = 1.78 × 10⁻⁴)?

2.44 %

The concentration of hydroxide ion in an aqueous solution at 25 °C is 3.6 × 10⁻⁴ M. What is the concentration of the hydronium ion?

2.8 × 10⁻¹¹ M

The pH of a solution is 3.45. What is the OH⁻ concentration in the solution?

2.8 × 10⁻¹¹ M

An unknown weak base with a concentration of 0.0910 M has a pH of 11.70. What is the Kb of this base?

2.9 × 10⁻⁴

When 0.200 mol of CaCO₃(s) and 0.300 mol of CaO(s) are placed in an evacuated, sealed 10.0-L container and heated to 1039 K, PCO₂ = 0.220 atm after equilibrium is established. CaCO₃(s) ⇌ CaO(s) + CO₂(g) Additional CO₂(g) is pumped into the container to raise the pressure to 0.550 atm. After equilibrium is re-established, what is the total mass (in g) of CaCO₃ in the container?

21.3 g You can use the ideal gas law to determine the moles CO₂ produced when the container is heated and then use an ICE table to determine the moles of CaCO₃ remaining. The moles of additional CO₂ added can also be determined using the ideal gas law and the increase in pressure. When equilibrium is reestablished, this additional CO₂ will have been converted to CaCO₃, and a second ICE table will show the new molar quantity of CaCO₃. Use the molar mass to convert to grams.

In an aqueous solution at 25 °C, if [H₃O⁺] = 2.4 × 10⁻⁴ M, then [OH⁻] is:

4.2 × 10⁻¹¹ M

The Kp for the reaction A (g) ⇌ 2 B (g) is 0.0450. What is Kp for the reaction 4 B (g) ⇌ 2 A (g)?

494 If a reaction is reversed, the equilibrium constant expression is inverted. Equilibrium constants are the products divided by the reactants. Coefficients become exponents. Because of this, multiplying the coefficients by 2 results in an exponent of 2. 1/(0.0450)2=494

The pOH of a solution is 9.70. What is the H⁺ concentration in the solution?

5.0 × 10⁻⁵ M

For the following reaction 3O₂(g) ⇌ 2O₃(g) Kc = 2.10 × 10⁻⁷ at a certain temperature. If [O₂] = 0.0495 M when at equilibrium, what is the equilibrium O₃ concentration?

5.05 × 10⁻⁶ M

What is the pH of a 0.0620 M solution of hydrocyanic acid, HCN (Ka = 4.9 × 10⁻¹⁰)?

5.26

2.3: For the reaction below, Kc = 9.2 × 10⁻⁵. Note Kc is sometimes called K. What is the equilibrium concentration of D if the reaction begins with 0.48 M A? A (aq) + 2 B (s) ⇌ C (s) + 2 D (aq)

6.6 × 10⁻³ M

An evacuated reaction vessel is filled with 0.80 atm of N₂ and 1.68 atm of Br₂. When equilibrium is established according to the reaction below, there are 1.42 atm of Br₂ remaining in the vessel. What is Kp for this reaction? 2 NBr₃ (g) ⇌ N₂ (g) + 3 Br₂ (g)

68

Consider the following two reactions occurring in the same vessel: A ⇌ B, K=0.01 A ⇌ C, K=0.02 What will there be most of in solution? A) A B) B C) C D) They'll all exist in equal amounts.

A) A The equilibrium constant is less than 1 for both reactions, meaning that there must be more reactants than products.

Consider the following equilibrium reaction: A (g) + B (s) ⇌ C (g) If Kp = 6 × 10⁻³, which species will have the highest partial pressure at equilibrium? A) A B) B C) C D) They'll all exist in equal amounts.

A) A The equilibrium constant is calculated by dividing the partial pressures of the products by the partial pressure of the reactants. Coefficients become exponents. Compounds which are solids and liquids have constant composition and therefore do not appear in the equilibrium expression. Kp=PCPA If the Kp is less than 1, this indicates that the partial pressure of A is larger than the partial pressure of C.

For which of the following equations would the value of Kp = Kc(RT)? Note Kc is sometimes called K. A) A (g) + 2 B (s) ⇌ C (s) + 2 D (g) B) 2 NO₂ (g) ⇌ N₂O₄ (g) C) 2 NBr₃ (g) ⇌ N₂ (g) + 3 Br₂ (g) D) 2 HI (g) ⇌ H₂ (g) + I₂ (g)

A) A (g) + 2 B (s) ⇌ C (s) + 2 D (g) In order for Kp=Kc(RT)Δn, the products should have 1 more mole of gas than the reactants.

Consider the reaction below. Which species is(are) the Brønsted-Lowry acid(s)? HF (aq) + NH₃ (aq) ⇌ NH₄⁺ (aq) + F⁻ (aq) A) HF, NH₄⁺ B) NH₃, NH₄⁺ C) F⁻, NH₄⁺ D) HF, NH₃

A) HF, NH₄⁺

The conjugate acid of H₂PO₄⁻ is A) H₃PO₄ B) HPO₄²⁻ C) PO₄³⁻ D) H₂PO₄

A) H₃PO₄

Which of the following is the correct expression for the pressure based equilibrium constant for the reaction: 4 NH₃ (g) + 7 O₂ (g) ⇌ 4 NO₂ (g) + 6 H₂O (g) A) I B) II C) III D) IV

A) I Equilibrium constants are the products divided by the reactants. Coefficients become exponents. In this case, the equilibrium constant would be represented as: Kp=(PNO2)4(PH2O)6/(PNH3)4(PO2)7

For the reaction below, Qp = 600. What must happen for the reaction to reach equilibrium? 2 A (g) + B (s) ⇌ 2 C (s) + D (g) Kp = 8210 A) The reaction needs to shift in the forward direction. B) The reaction needs to shift in the reverse direction. C) The reaction is already at equilibrium and no shift needs to take place. D) There is not enough information to determine how the reaction will reach equilibrium.

A) The reaction needs to shift in the forward direction. Kp>Qp and this indicates that the reaction will shift in the forward direction.

For a particular reaction K = 98000. What can be said about this reaction? A) There are many more products than reactants in the equilibrium mixture. B) There are many more reactants than products in the equilibrium mixture. C) There are roughly equal amounts of reactants and products in the equilibrium mixture. D) The reaction has not yet reached equilibrium because K does not equal 1.

A) There are many more products than reactants in the equilibrium mixture. The equilibrium constant is more than 1, meaning that there must be more products than reactants. Because the number is much greater than 1, we can say that there are many more products than reactants in the equilibrium mixture.

Rank the following in order of most acidic to least acidic. Solution Solution X pH = 8.50 Solution Y pOH = 4.30 Solution Z [OH-] = 4.2 x 10⁻⁹ M A) Z > X > Y B) Y > X > Z C) Y > Z > X D) X > Y > Z

A) Z > X > Y

When NO₂ dimerizes (two molecules join together to form a 'dimer') into N₂O₄, an equilibrium is reached and in the process this reaction produces heat. If you increase the temperature of the chamber in which both NO₂ and N₂O₄ reside, you would observe A) an increase in NO₂. B) an increase in N₂O₄. C) no change in concentration. D) a decrease in the reaction rate.

A) an increase in NO₂. Think of the heat as a product in the equation. As the products are increased, the reaction will shift to the left to create more reactants to reach equilibrium.

For the reaction: Mg(OH)₂ (s) ⇌ Mg²⁺ (aq) + 2 OH⁻ (aq) Adding Mg(OH)₂ will A) have no effect. B) increase the concentration of the hydroxide ions. C) decrease the concentration of the magnesium ions. D) change the value of the equilibrium constant.

A) have no effect. Compounds which are solids and liquids have constant composition and therefore do not appear in the equilibrium expression. Adding more solid will have no effect.

Forming solution A from liquid B and liquid C is endothermic. Increasing the temperature of the solution will A) increase the solubility of B B) decrease the solubility of B C) have no effect on the solubility of B

A) increase the solubility of B The solution process requires energy (is endothermic), and can be represented by this equilibrium process:liquid B+liquid C+energy⇌solution Aliquid B+liquid C+energy⇌solution A Increasing the temperature by adding energy will force this equilibrium to the right, by Le Chatelier's Principle, which states that a chemical system at equilibrium will respond in an opposite manner to an applied force. This will push the reaction towards the product, causing more of liquid B (as well as liquid C) to be formed into the solution A.

If the reaction quotient (Q) for a given reaction is less than the equilibrium constant (K) then A) the reaction will proceed in the forward direction. B) The reaction will proceed in the reverse direction. C) the reaction is at equilibrium.

A) the reaction will proceed in the forward direction. If the reaction quotient (Q) for a given reaction is less than the equilibrium constant (K) then the reaction will proceed in the forward direction.

Which one of the following is a strong base? A) Mg(OH)₂ B) Ca(OH)₂ C) NH₃ D) CH₃OH

B) Ca(OH)₂ These are the strong bases:LiOH,NaOH,KOH,RbOH,CsOH,Ca(OH)2,Sr(OH)2, Ba(OH)2, and Mg(OH)2

Consider the table of weak acids below. Which of the following bases would be the strongest weak base? Weak Acid Kₐ HCN 4.9 x 10⁻¹⁰ H₂O₂ 2.4 x 10⁻¹² HIO 2.3 x 10⁻¹¹ HBrO 2.5 x 10⁻⁹ A) CN⁻ B) HO₂⁻ C) IO⁻ D) BrO⁻

B) HO₂⁻

Which of the following is an amphoteric species? A) H₂SO₃ B) HSO₃⁻ C) SO₃²⁻

B) HSO₃⁻

Consider the reaction below. Which species are conjugate acid/base pairs? HSO₃⁻ (aq) + HCN (aq) ⇌ H₂SO₃ (aq) + CN⁻ (aq) A) HSO₃⁻, CN⁻ B) HSO₃⁻, H₂SO₃ C) H₂SO₃, CN⁻ D) HCN, H₂SO₃

B) HSO₃⁻, H₂SO₃

Which of the following will be the strongest acid? A) H₂O B) H₂Te C) H₂S D) H₂Se

B) H₂Te The weaker the H-A bond strength, the stronger the acid.

Consider the following energy diagram and determine which of the following statements is true. A) K = k_forward/k_reverse > 1 B) K = k_forward/k_reverse < 1 C) K = k_reverse/k_forward > 1 D) K = k_reverse/k_forward < 1

B) K = k_forward/k_reverse < 1 The equilibrium constant is equal to the rate of the forward reaction divided by the rate of the reverse reaction. In this case, the activation energy is higher in the forward . The magnitude of the rate constants cannot be known here, but since Ea is higher for the forward reaction, kf will be smaller than kr and the ratio of is kfkr<1<1.

When a system is at dynamic equilibrium, the rates of the forward and reverse reactions are equal.For the reaction below, the partial pressure of NO₂ is 0.50 atm and the partial pressure of N₂O₄ is 0.25 atm. What must happen for the reaction to reach equilibrium? 2 NO₂ (g) ⇌ N₂O₄ (g) Kp = 0.25 A) The reaction needs to shift in the forward direction. B) The reaction needs to shift in the reverse direction. C) The reaction is already at equilibrium and no shift needs to take place. D) There is not enough information to determine how the reaction will reach equilibrium.

B) The reaction needs to shift in the reverse direction. The reaction quotient is calculated by dividing the partial pressures of the products by the partial pressures of the reactants. Coefficients become exponents. Use the given pressures to calculate the reaction quotient and then compare to the given equilibrium constant. Qp=PN2O4(PNO2)2=(0.25)(0.50)2=1=24(2)2=(0.25)(0.50)2=1 This is the larger than the given KP indicating that the reaction has more products and needs to shift to the reverse direction to reach equilibrium.

2.2 Consider the following acidic equilibrium: H₂CO₃(aq) + H₂O(l) ⇌ HCO₃⁻(aq) + H₃O⁺(aq). If you add NaHCO₃ to this solution, which of the following will occur? A) The reaction quotient will decrease. B) The reaction will shift in the reverse direction. C) The equilibrium constant will increase. D) No changes to the equilibrium positions will take place.

B) The reaction will shift in the reverse direction. If you add NaHCO3NaHCO3 to this solution, the reaction will shift in the reverse direction to reestablish equilibrium

The weak acid HY is much stronger than weak acid HX. Which one of the following statements is true? A) Y⁻ is a stronger base than X⁻. B) Y⁻ is a weaker base than X⁻. C) Y⁻ and X⁻ will be bases of approximately the same strength.

B) Y⁻ is a weaker base than X⁻.

2.7: The reason Al³⁺ can act as an acid is because A) it is insoluble with hydroxide ions. B) it forms a complex ion with water molecules that allow it to attract hydroxide ions. C) it is soluble in water. D) it has a +3 charge.

B) it forms a complex ion with water molecules that allow it to attract hydroxide ions. Al3+ can act as an acid is because it forms a complex ion with water molecules that allow it to attract hydroxide ions.

An equilibrium is established for the reaction 2 CO(g) + MoO₂(s) ⇌ 2 CO₂(g) + Mo(s). Kp = 0.0152 and Q = 0.0336. Which way does the reaction need to shift to reach equilibrium?

B) reverse

Which of the following statements best described Le Chatelier's Principle? A) Reactions can never really reach equilibrium. B) A reaction which is at equilibrium will always try to stay at equilibrium. C) A reaction which is at equilibrium, when disturbed, will react appropriately to reestablish equilibrium. D) All reactions will eventually run to equilibrium.

C) A reaction which is at equilibrium, when disturbed, will react appropriately to reestablish equilibrium. Le Chatelier's Principle states that a reaction which is at equilibrium, when disturbed, will react appropriately to reestablish equilibrium.

Which one of the following correctly shows the weak acid equilibrium for trichloroacetic acid, CCl₃COOH? A) CCl₃COOH (aq) ⇌ CCl₃CO⁺ (aq) + OH⁻ (aq) B) CCl₃COOH (aq) + H₂O (l) ⇌ CCl₃COOH₂⁺ (aq) + OH⁻ (aq) C) CCl₃COOH (aq) + H₂O (l) ⇌ CCl₃COO⁻ (aq) + H₃O⁺ (aq) D) CCl₃COOH (aq) + H₂O (l) ⇌ CCl₃CO(OH)₂⁻ (aq) + H⁺ (aq)

C) CCl₃COOH (aq) + H₂O (l) ⇌ CCl₃COO⁻ (aq) + H₃O⁺ (aq)

Which one of the following 1.0 M solutions would have the lowest pH? Weak Base Kb C₅H₅N 1.7 x 10⁻⁹ HONH₂ 1.1 x 10⁻⁸ C₆H₅NH₂ 4.3 x 10⁻¹⁰ H₂NNH₂ 1.3 x 10⁻⁶ A) C₅H₅N B) HONH₂ C) C₆H₅NH₂ D) H₂NNH₂

C) C₆H₅NH₂

Which one of the following is a strong acid? A) HNO₂ B) HF C) HClO₄ D) HC₂H₃O₂

C) HClO₄ Strong acids include: HCl, HBr, HI, HNO3, HClO4, HClO3, H2SO4

Which of the following is a conjugate acid/base pair? A) H₃PO₄, PO₄³⁻ B) H₂PO₄⁻, PO₄³⁻ C) HPO₄²⁻, PO₄³⁻ D) H₃PO₄, HPO₄²⁻

C) HPO₄²⁻, PO₄³⁻

The conjugate base of HPO₃²⁻ is A) HPO₃⁻ B) H₂PO₃⁻ C) PO₃³⁻ D) H₃PO₃

C) PO₃³⁻

2.5: A decrease of pH by 3 implies A) The H⁺ concentration triples. B) The OH⁻ concentration decreases by a factor of 3. C) The OH⁻ concentration decreases by a factor of 1000. D) The H⁺ concentration decreases by a factor of 1000.

C) The OH⁻ concentration decreases by a factor of 1000.

2.1 Which of the following is true for a reaction at equilibrium? A) The rate of the forward reaction is greater than the rate of the reverse reaction. B) The rate of the forward reaction is less than the rate of the reverse reaction. C) The rate of the forward reaction is equal to the rate of the reverse reaction. D) The rates of the forward and reverse reactions become zero because the reaction stops. E) The rates of the forward and reverse reactions can no longer be determined.

C) The rate of the forward reaction is equal to the rate of the reverse reaction. When a reaction is at equilibrium there is no further change in the concentrations of the reactants and products. That means they must be formed at the same rate as they are breaking down, so the rate of the forward reaction is equal to the rate of the reverse reaction.

Which of the following statements best describes what occurs at equilibrium? A) The reaction has stopped so the concentrations of reactants and products do not change. B) The amount of products are equal to the amount of reactants. C) The rate of the reaction in the forward direction is equal to the rate of the reaction in the reverse direction. D) The rate constant for the forward reaction equals the rate constant for the reverse reaction.

C) The rate of the reaction in the forward direction is equal to the rate of the reaction in the reverse direction. When a system is at dynamic equilibrium, the rates of the forward and reverse reactions are equal.

For the reaction below, the concentration of HI is 0.210 M and the concentrations of H₂, and I₂ are both 0.564 M. What must happen for the reaction to reach equilibrium? 2 HI (g) ⇌ H₂ (g) + I₂ (g) Kc = 7.21 (Note Kc is sometimes called K.) A) The reaction needs to shift in the forward direction. B) The reaction needs to shift in the reverse direction. C) The reaction is already at equilibrium and no shift needs to take place. D) There is not enough information to determine how the reaction will reach equilibrium.

C) The reaction is already at equilibrium and no shift needs to take place. The reaction quotient is calculated by dividing the concentrations of the products by the concentrations of the reactants. Coefficients become exponents. Use the given concentrations to calculate the reaction quotient and then compare to the equilibrium constant. Qc=[H2][I2]/[HI]2=(0.564)(0.564)/(0.210)2=7.21=[2][2][]2=(0.564)(0.564)(0.210)2=7.21 This is the same as the given Kc indicating that the reaction is already at equilibrium.

Consider the reaction: 2 A (g) + B (s) ⇌ 2 C (s) + D (g) To increase the partial pressure of D at equilibrium, you could A) add B. B) remove C. C) add A. D) add Ar (g).

C) add A. Adding more A would cause the reaction to shift in the forward reaction to create more D, causing an increase in the partial pressure of D.

Consider the following reaction: 2 SO₂(g) + O₂(g) ⇌ 2 SO₃(g). If you decrease the volume of the reaction chamber, you would observe A) an increase in SO₂. B) an increase in O₂. C) an increase in SO₃. D) both (A) and (B).

C) an increase in SO₃. Decreasing the volume increases the pressure, which will decrease the number of molecules on the side of the reaction with more gas.

Consider the reaction below. Which of the following would increase the partial pressure of B at equilibrium? A (s) + B (g) ⇌ C (g) ΔH < 0 A) adding A. B) increasing the total volume of the container. C) increasing the temperature. D) removing C.

C) increasing the temperature. A negative ΔH indicates that this is an exothermic reaction with energy being released in the forward reaction. Increasing the temperature would shift the reaction to the left to create more reactants to reach equilibrium.

Which of the following changes would cause the reaction below to shift in the forward direction to reestablish equilibrium? 2 NBr₃ (g) ⇌ N₂ (g) + 3 Br₂ (g) A) adding a catalyst. B) adding Ar (g). C) increasing the total volume of the container. D) adding N₂.

C) increasing the total volume of the container. An increase in volume would result in a decrease in pressure. This would shift to the forward direction to produce more products.

2.4 HI is an Arrhenius acid because A) it is a polar molecule. B) it can dissolve in water. C) it produces hydronium ions in solution. D) it produces hydroxide ions in solution.

C) it produces hydronium ions in solution.

When a system is at dynamic equilibrium, A) no reactions are occurring. B) a reaction is occurring in only one direction. C) the rates of the forward and reverse reactions are equal. D) all of the reactants have been converted to products

C) the rates of the forward and reverse reactions are equal. When a system is at dynamic equilibrium, the rates of the forward and reverse reactions are equal.

Consider the following diagrams which show the progress for the reaction A (blue) ⇌ B (red). The equilibrium constant (K) for this reaction is 0.8. At which point does the reaction reach equilibrium? A) I B) II C) III D) IV (Graph with 5 rectangles and blue/red circles inside)

C. III The equilibrium constant is the products divided by the reactants. An equilibrium constant or K value of 0.8 is consistent where the ratio of product to reactant is 4:5.

Consider the equilibrium constant below. Which of the following reactions matches this equilibrium constant? A) 2 A (s) + B (g) ⇌ 2 C (g) + D (s) B) 2 A (g) + B (g) ⇌ 2 C (s) + D (g) C) D (g) + C (s) ⇌ 2 A (g) + B (s) D) 2 A (g) + B (s) ⇌ 2 C (s) + D (g)

D) 2 A (g) + B (s) ⇌ 2 C (s) + D (g) Equilibrium constants are the products divided by the reactants. Coefficients become exponents. In this case, the equilibrium constant shows that the product is D and the reactant is A. It also shows the coefficient for A is 2. Compounds which are solids and liquids have constant composition and therefore do not appear in the equilibrium expressions, so they can also be part of the chemical reaction. At minimum, the balanced chemical reaction would be 2A ⇌D2A ⇌D. A and D can be either in gaseous or aqueous form.

Consider the equilibrium constant below. Which of the following reactions would fit this equilibrium constant? A) A (g) + B (g) ⇌ C (g) B) A (g) ⇌ B (g) + 2 C (g) C) B (g) + C (g) ⇌ A (g) D) B (g) + 2 C (g) ⇌ A (g)

D) B (g) + 2 C (g) ⇌ A (g) Equilibrium constants are the products divided by the reactants. Coefficients become exponents. In this case, the equilibrium constant shows that the product is A and the reactants are B and C. It also shows the coefficient for C is 2. The balanced chemical reaction would be B+2C⇌AB+2C⇌A.

Which one of the following is the strongest weak acid? Weak Acid Kₐ HCN 4.9 x 10⁻¹⁰ H₂O₂ 2.4 x 10⁻¹² HIO 2.3 x 10⁻¹¹ HBrO 2.5 x 10⁻⁹ A) HCN B) H₂O₂ C) HIO D) HBrO

D) HBrO

Which of the following will be the strongest acid? A) HIO B) HIO₂ C) HIO₃ D) HIO₄

D) HIO₄

Which of the following will be the weakest acid? A) H₂SO₄ B) H₂SO₃ C) HSO₄⁻ D) H₂S

D) H₂S

Which of the following acids would be expected to be strongest? A) Na⁺ B) Ca²⁺ C) Li⁺ D) Mg²⁺

D) Mg²⁺

An equilibrium is established for the reaction 2 CO(g) + MoO₂(s) ⇌ 2 CO₂(g) + Mo(s). An equilibrium is established for the reaction 2 CO(g) + MoO₂(s) ⇌ 2 CO₂(g) + Mo(s). Which of the following is the correct expression for Kp?

D) See image P2co2/P2co

2.6: A solution has a pH of 13.20. We can conclude that A) the solution is very acidic. B) the solution is only slightly acidic. C) the solution is only slightly basic. D) The solution is very basic.

D) The solution is very basic.

A solution has a pH of 13.20. We can conclude that A) the solution is very acidic. B) the solution is only slightly acidic. C) the solution is only slightly basic. D) The solution is very basic.

D) The solution is very basic.

Which of the following changes would have no effect on the equilibrium position of the reaction below? 2 NOBr (g) ⇌ 2 NO (g) + Br₂ (g) A) adding NOBr. B) removing NO C) doubling the concentration of NO at the same time as the concentration of Br₂ is cut in half. D) cutting the concentrations of both NOBr and NO in half.

D) cutting the concentrations of both NOBr and NO in half. Since the concentration of NO is squared in the equilibrium constant expression and so is NOBr, cutting both concentrations in half would cancel each other out.

Consider the reaction below. Which of the following would increase the partial pressure of A at equilibrium? A (g) + B (g) ⇌ C (g) ΔH > 0 A) adding B B) removing C C) increasing temperature D) decreasing temperature

D) decreasing temperature A positive ΔHΔH indicates that this is an endothermic reaction with energy being required for the forward reaction to occur. Decreasing the temperature would shift the reaction to the left to create more reactants to reach equilibrium.

NaOH is a Brønsted-Lowry base because A) it is a polar molecule. B) it can dissolve in water. C) it is a hydroxide donor. D) it is a proton acceptor.

D) it is a proton acceptor.

For a given reaction, if the temperature of the reaction vessel is increased, the equilibrium constant will: A) decrease. B) increase C) stay the same. D) more information about the reaction is needed.

D) more information about the reaction is needed. Heat is either considered a reactant in an endothermic reaction or as a product in an exothermic reaction. More information is needed to know the effect this will have.

Consider the following reaction: CH₃COOH(aq) + H₂O(l) ⇌ CH₃COO⁻(aq) + H₃O⁺(aq). An increase in the pressure of the chamber where this reaction takes place will result in A) an increase in CH₃COOH. B) an increase in CH₃COO⁻. C) an increase in H₃O⁺. D) both (B) and (C). E) no change.

E) no change A change in pressure will only affect an equilibrium with gaseous species.

Consider the reaction of CO.....

I: - C: - E:- I: 0.0750 C: -0.0350 E: 0.0400 I: 0 C: 0.0700 E: 0.0700

Consider the reaction of N2O ....

I: 0.200 C: -0.0100 E: 0.190 I: 0.0560 C: -0.0150 E: 0.0410 I: 0 C: 0.0200 E: 0.0200

At High Temperatures: SO4....

I: 2.00 C: -1.30 E: 0.70 I: 2.00 C: -1.30 E: 0.70 I: 0 C: 1.30 E: 1.30 I: 0 C: 1.30 E: 1.30

Construct the expression for Kc for the following reaction. 2 Ag(s) + Zn2+ (aq) —- 2 Ag+(aq) + Zn(s)

Kc= [Ag+]2/[Zn2+]

Construct the expression for Kc for the following reaction. CH4(g) + 2 H2S(g) —- CS2(g) + 4 H2(g)

Kc= [CS2][H2]4/ [CH4][H2S]2

Write the formula of the conjugate base of the Brønsted-Lowry acid, NH₄⁺

NH₃

Write the formula of the conjugate base of the Brønsted-Lowry acid, HPO₄²⁻

PO₄³⁻

Construct the equilibrium system described by the chemical reaction below. For the reaction, Kc= 2.19 x10-10 at a particular temperature. Calculate the value of Qc for the initial set reaction conditions: 4.50 x 10-2 M COCl2, 1.10 x 10-7 M CO, 2.25 x 10-6 M Cl2. COCl2(g) —- CO(g) + Cl2(g)

Qc= [1.10 x 10-7][2.25 x 10-6]/ [4.50 x 10-2] = 5.50 x 10-12