Question 1

The equilibrium between carbon dioxide gas and carbonic acid is very important in biology and environmental science, and is shown below.CO₂(aq) + H₂O(l) ⇌ H₂CO₃(aq) Based on the equilibrium constant reported for this reaction (K_c = 1.70 * 10^-3), there will be more carbon dioxide in solution than carbonic acid.

Accepted Answer

The equilibrium constant (K) for the reaction CO2(aq) + H2O(l) ⇌ H2CO3(aq) is small (1.70 × 10^-3), indicating that the reaction favors the reactants (CO2 and H2O) over the product (H2CO3), meaning there will be more CO2 in solution than carbonic acid at equilibrium.

Question 2

What is the correct equilibrium constant expression for this reaction 2HI(g) ⇌ H₂(g) + I₂(g)

Accepted Answer

The correct equilibrium constant expression for the given reaction takes into account the stoichiometry of the reactants and products. For the reaction 2HI(g) ⇌ H₂(g) + I₂(g), the equilibrium constant expression is Kc = [H₂][I₂]/[HI]^2, reflecting the squared concentration of HI due to its coefficient of 2 in the balanced equation.

Question 3

Two moles of PCl₅ are placed in a 5.0 L container. Dissociation takes place according to the equation PCl₅(g) ⇌ PCl₃(g) + Cl₂(g). At equilibrium, 0.40 mol of Cl₂ are present. Calculate the equilibrium constant (K_c) for this reaction under the conditions of this experiment.

Accepted Answer

Initially, 2 moles of PCl5 are present in a 5.0 L container, so the initial concentration of PCl5 is 0.4 M. At equilibrium, 0.40 mol of Cl2 is present, meaning 0.40 mol of PCl5 has dissociated, resulting in 0.40 mol of PCl3 and 0.40 mol of Cl2. The equilibrium concentrations are: [PCl5] = 0.4 - 0.08 = 0.32 M, [PCl3] = 0.08 M, [Cl2] = 0.08 M. Kc = ([PCl3][Cl2])/[PCl5] = (0.08 * 0.08) / 0.32 = 0.020.

Question 4

The equilibrium constant expression for the following reaction CuO(s) + H₂(g) ⇌ Cu(s) + H₂O(g) is K_c = [H₂]/[H₂O].

Accepted Answer

The equilibrium constant expression, $K_c$, for a reaction only includes the concentrations of gases and aqueous solutions. Since CuO(s) and Cu(s) are solids, they do not appear in the expression. The correct expression should involve the concentrations of the gaseous species only, and it should be $K_c = \frac{[HS_{2}O]}{[H_2S]}$, assuming H₂ and H₂O are meant to represent H2S and H2SO, respectively.

Question 5

The K_c for the reaction CO₂(g) + H₂(g) ⇌ H₂O(g) + CO(g) is 1.6 at about 990ºC. Calculate the number of moles of carbon dioxide in the final equilibrium system obtained by initially adding 1.00 mol of H₂, 2.00 mol of CO₂, 0.750 mol of H₂O, and 1.00 mol of CO to a 5.00 L reactor at 990ºC.

Accepted Answer

The answer of The K_c for the reaction CO₂(g) +...

Question 6

Consider the following equilibrium: 4NH₃(g) + 3O₂(g) ⇌ 2N₂(g) + 6H₂O(g) + 1531 kJ The concentrations of the reactants would decrease after ammonia was added to the system.

Accepted Answer

According to Le Chatelier's principle, adding ammonia to this equilibrium system would shift the equilibrium to the right to counteract the increase in concentration of reactants. Therefore, the concentrations of the reactants would decrease, making option A true.

Question 7

When the reaction 2O₃(g) ⇌ 3O₂(g), for which K_p = 3.0 * 10²⁶ at 773ºC, is at equilibrium, the mixture will contain very little O₂ as compared to O₃.

Accepted Answer

The given Kp value (3.0 × 10^26) indicates a strong tendency for the reaction to proceed towards the formation of products (O₂), suggesting that at equilibrium, there will be a significant amount of O₂ compared to O₃.

Question 8

The equilibrium constant for the chemical equation 2NO(g) + O₂(g) ⇌ 2NO₂(g) is two times the equilibrium constant for the chemical equation NO(g) + ¹/₂O₂(g) ⇌ NO₂(g).

Accepted Answer

The equilibrium constant (K) for a reaction is determined by the stoichiometry of the reaction as written. Doubling the coefficients in a chemical equation squares the equilibrium constant, not doubles it. Therefore, if the second equation represents the first equation with all coefficients halved, its equilibrium constant would be the square root of the first, not half.

Question 9

For the reaction H₂(g) + I₂(g) ⇌ 2HI(g), K_P = K_c.

Accepted Answer

The equality between the reaction quotient (Kc) and the equilibrium constant (K) indicates that the equilibrium constant expression is written using the concentration of the substances involved in the reaction. This information is given by the formulation of the question, where both K values ​​are equal, implying that the balance constant expression uses the molar concentration of the substances involved in the reaction.

Question 10

Consider the following equilibrium: 4NH₃(g) + 3O₂(g) ⇌ 2N₂(g) + 6H₂O(g) + 1531 kJ The concentrations of the reactants will increase when the temperature is increased.

Accepted Answer

According to Le Chatelier's principle, increasing the temperature of an exothermic reaction will shift the equilibrium to the left, decreasing the concentrations of the reactants.

Question 11

The K_c for the reaction CO₂(g) + H₂(g) ⇌ H₂O(g) + CO(g) is 1.6 at about 990ºC. Calculate the number of moles of carbon monoxide in the final equilibrium system obtained by initially adding 1.00 mol of H₂, 2.00 mol of CO₂, 0.750 mol of H₂O, and 1.00 mol of CO to a 5.00 L reactor at 990ºC.

Accepted Answer

The answer of The K_c for the reaction CO₂(g) +...

Question 12

Calcium carbonate decomposes at high temperatures to give calcium oxide and carbon dioxide as shown below.CaCO₃(s) ⇌ CaO(s) + CO₂(g) The K_P for this reaction is 1.16 at 800^$\circ$C. A 5.00 L vessel containing 10.0 g of CaCO₃(s) was evacuated to remove the air, sealed, and then heated to 800^$\circ$C. Ignoring the volume occupied by the solid, what will be the overall mass percent of carbon in the solid once equilibrium is reached

Accepted Answer

The answer of Calcium carbonate decomposes at high temperatures to...

Question 13

Equilibrium constants are known for the following reactions: S(s) + ³/₂O₂(g) ⇌ SO₃(g) K_c = 9.2 * 10²³ SO₃(g) ⇌ SO₂(g) + ¹/₂O₂(g) K_c = 4.8 * 10^{- 4} Thus, for the reaction S(s) + O₂(g) ⇌ SO₂(g), K_c = 4.4 * 10²⁰.

Accepted Answer

The equilibrium constant for the reaction given is indeed 4.4x10^-10, which is provided in the information given.

Question 14

Consider the following equilibrium: 4NH₃(g) + 3O₂(g) ⇌ 2N₂(g) + 6H₂O(g) + 1531 kJ The concentrations of the products will increase when the temperature is increased.

Accepted Answer

The reaction is exothermic, so increasing the temperature will shift the equilibrium to the left, favoring the reactants and decreasing the concentration of the products.

Question 15

The K_c for the reaction CO₂(g) + H₂(g) ⇌ H₂O(g) + CO(g) is 1.6 at about 990ºC. Calculate the number of moles of water in the final equilibrium system obtained by initially adding 1.00 mol of H₂, 2.00 mol of CO₂, 0.750 mol of H₂O, and 1.00 mol of CO to a 5.00 L reactor at 990ºC.

Accepted Answer

The answer of The K_c for the reaction CO₂(g) +...

Question 16

The K_c for the reaction CO₂(g) + H₂(g) ⇌ H₂O(g) + CO(g) is 1.6 at about 990ºC. Calculate the number of moles of hydrogen gas in the final equilibrium system obtained by initially adding 1.00 mol of H₂, 2.00 mol of CO₂, 0.750 mol of H₂O, and 1.00 mol of CO to a 5.00 L reactor at 990ºC.

Accepted Answer

To find the equilibrium moles of H₂, set up an ICE table and use the equilibrium constant expression Kc = [H₂O][CO]/[CO₂][H₂]. Solve for the change in moles (x) and calculate the equilibrium moles of H₂. The correct answer is 0.62 mol.

Question 17

Consider the equilibrium equation C(s) + H₂O(g) ⇌ CO(g) + H₂(g), $\Delta$H = 2296 J. The reaction will shift towards products if the volume of the container is decreased.

Accepted Answer

The reaction involves equal moles of gas on both sides (1 mole of gas reacting to produce 1 mole of gas), so changing the volume will not affect the position of equilibrium according to Le Chatelier's principle.

Question 18

Consider the following equilibrium: 4NH₃(g) + 3O₂(g) ⇌ 2N₂(g) + 6H₂O(g) + 1531 kJ The concentrations the reactants would increase after nitrogen gas was removed from the system.

Accepted Answer

According to Le Chatelier's principle, removing a reactant (in this case, nitrogen gas) from an equilibrium system will cause the system to shift towards the reactants side to counteract the change. However, nitrogen gas is not a reactant in the given chemical equation, so removing it would not affect the concentrations of the reactants in this system.

Question 19

Calcium carbonate decomposes at high temperatures to give calcium oxide and carbon dioxide as shown below.CaCO₃(s) ⇌ CaO(s) + CO₂(g) The K_P for this reaction is 1.16 at 800^$\circ$C. A 5.00 L vessel containing 10.0 g of CaCO₃(s) was evacuated to remove the air, sealed, and then heated to 800^$\circ$C. Ignoring the volume occupied by the solid, what will be the mass of the solid in the vessel once equilibrium is reached

Accepted Answer

At equilibrium, the partial pressure of CO2 will be equal to Kp. Using the ideal gas law, we can calculate the moles of CO2 and thus the moles of CaCO3 decomposed. Subtracting this from the initial moles of CaCO3 gives the remaining mass of solid.

Quiz 14: Chemical Equilibrium

What is the correct equilibrium constant expression for this reaction 2HI(g) ⇌ H₂(g) + I₂(g)

Two moles of PCl₅ are placed in a 5.0 L container. Dissociation takes place according to the equation PCl₅(g) ⇌ PCl₃(g) + Cl₂(g) . At equilibrium, 0.40 mol of Cl₂ are present. Calculate the equilibrium constant (K_c) for this reaction under the conditions of this experiment.

The equilibrium constant expression for the following reaction CuO(s) + H₂(g) ⇌ Cu(s) + H₂O(g) is K_c = [H₂]/[H₂O].

Consider the following equilibrium: 4NH₃(g) + 3O₂(g) ⇌ 2N₂(g) + 6H₂O(g) + 1531 kJ The concentrations of the reactants would decrease after ammonia was added to the system.

When the reaction 2O₃(g) ⇌ 3O₂(g), for which K_p = 3.0 * 10²⁶ at 773ºC, is at equilibrium, the mixture will contain very little O₂ as compared to O₃.

The equilibrium constant for the chemical equation 2NO(g) + O₂(g) ⇌ 2NO₂(g) is two times the equilibrium constant for the chemical equation NO(g) + ¹/₂O₂(g) ⇌ NO₂(g).

For the reaction H₂(g) + I₂(g) ⇌ 2HI(g), K_P = K_c.

Consider the following equilibrium: 4NH₃(g) + 3O₂(g) ⇌ 2N₂(g) + 6H₂O(g) + 1531 kJ The concentrations of the reactants will increase when the temperature is increased.

Equilibrium constants are known for the following reactions: S(s) + ³/₂O₂(g) ⇌ SO₃(g) K_c = 9.2 * 10²³ SO₃(g) ⇌ SO₂(g) + ¹/₂O₂(g) K_c = 4.8 * 10^{- 4} Thus, for the reaction S(s) + O₂(g) ⇌ SO₂(g), K_c = 4.4 * 10²⁰.

Consider the following equilibrium: 4NH₃(g) + 3O₂(g) ⇌ 2N₂(g) + 6H₂O(g) + 1531 kJ The concentrations of the products will increase when the temperature is increased.

The K_c for the reaction CO₂(g) + H₂(g) ⇌ H₂O(g) + CO(g) is 1.6 at about 990ºC. Calculate the number of moles of water in the final equilibrium system obtained by initially adding 1.00 mol of H₂, 2.00 mol of CO₂, 0.750 mol of H₂O, and 1.00 mol of CO to a 5.00 L reactor at 990ºC.

Consider the equilibrium equation C(s) + H₂O(g) ⇌ CO(g) + H₂(g), $\Delta$ H = 2296 J. The reaction will shift towards products if the volume of the container is decreased.

Consider the following equilibrium: 4NH₃(g) + 3O₂(g) ⇌ 2N₂(g) + 6H₂O(g) + 1531 kJ The concentrations the reactants would increase after nitrogen gas was removed from the system.

Quiz 14: Chemical Equilibrium

What is the correct equilibrium constant expression for this reaction 2HI(g) ⇌ H2(g) + I2(g)

Two moles of PCl5 are placed in a 5.0 L container. Dissociation takes place according to the equation PCl5(g) ⇌ PCl3(g) + Cl2(g) . At equilibrium, 0.40 mol of Cl2 are present. Calculate the equilibrium constant (Kc) for this reaction under the conditions of this experiment.

The equilibrium constant expression for the following reaction CuO(s) + H2(g) ⇌ Cu(s) + H2O(g) is Kc = [H2]/[H2O].

The Kc for the reaction CO2(g) + H2(g) ⇌ H2O(g) + CO(g) is 1.6 at about 990ºC. Calculate the number of moles of carbon dioxide in the final equilibrium system obtained by initially adding 1.00 mol of H2, 2.00 mol of CO2, 0.750 mol of H2O, and 1.00 mol of CO to a 5.00 L reactor at 990ºC.

Consider the following equilibrium: 4NH3(g) + 3O2(g) ⇌ 2N2(g) + 6H2O(g) + 1531 kJ The concentrations of the reactants would decrease after ammonia was added to the system.

When the reaction 2O3(g) ⇌ 3O2(g), for which Kp = 3.0 * 1026 at 773ºC, is at equilibrium, the mixture will contain very little O2 as compared to O3.

The equilibrium constant for the chemical equation 2NO(g) + O2(g) ⇌ 2NO2(g) is two times the equilibrium constant for the chemical equation NO(g) + 1/2O2(g) ⇌ NO2(g).

For the reaction H2(g) + I2(g) ⇌ 2HI(g), KP = Kc.

Consider the following equilibrium: 4NH3(g) + 3O2(g) ⇌ 2N2(g) + 6H2O(g) + 1531 kJ The concentrations of the reactants will increase when the temperature is increased.

The Kc for the reaction CO2(g) + H2(g) ⇌ H2O(g) + CO(g) is 1.6 at about 990ºC. Calculate the number of moles of carbon monoxide in the final equilibrium system obtained by initially adding 1.00 mol of H2, 2.00 mol of CO2, 0.750 mol of H2O, and 1.00 mol of CO to a 5.00 L reactor at 990ºC.

Equilibrium constants are known for the following reactions: S(s) + 3/2O2(g) ⇌ SO3(g) Kc = 9.2 * 1023 SO3(g) ⇌ SO2(g) + 1/2O2(g) Kc = 4.8 * 10- 4 Thus, for the reaction S(s) + O2(g) ⇌ SO2(g), Kc = 4.4 * 1020.

Consider the following equilibrium: 4NH3(g) + 3O2(g) ⇌ 2N2(g) + 6H2O(g) + 1531 kJ The concentrations of the products will increase when the temperature is increased.

The Kc for the reaction CO2(g) + H2(g) ⇌ H2O(g) + CO(g) is 1.6 at about 990ºC. Calculate the number of moles of water in the final equilibrium system obtained by initially adding 1.00 mol of H2, 2.00 mol of CO2, 0.750 mol of H2O, and 1.00 mol of CO to a 5.00 L reactor at 990ºC.

The Kc for the reaction CO2(g) + H2(g) ⇌ H2O(g) + CO(g) is 1.6 at about 990ºC. Calculate the number of moles of hydrogen gas in the final equilibrium system obtained by initially adding 1.00 mol of H2, 2.00 mol of CO2, 0.750 mol of H2O, and 1.00 mol of CO to a 5.00 L reactor at 990ºC.

Consider the equilibrium equation C(s) + H2O(g) ⇌ CO(g) + H2(g), Δ\DeltaΔ H = 2296 J. The reaction will shift towards products if the volume of the container is decreased.

Consider the following equilibrium: 4NH3(g) + 3O2(g) ⇌ 2N2(g) + 6H2O(g) + 1531 kJ The concentrations the reactants would increase after nitrogen gas was removed from the system.

What is the correct equilibrium constant expression for this reaction 2HI(g) ⇌ H₂(g) + I₂(g)

Two moles of PCl₅ are placed in a 5.0 L container. Dissociation takes place according to the equation PCl₅(g) ⇌ PCl₃(g) + Cl₂(g) . At equilibrium, 0.40 mol of Cl₂ are present. Calculate the equilibrium constant (K_c) for this reaction under the conditions of this experiment.

The equilibrium constant expression for the following reaction CuO(s) + H₂(g) ⇌ Cu(s) + H₂O(g) is K_c = [H₂]/[H₂O].

Consider the following equilibrium: 4NH₃(g) + 3O₂(g) ⇌ 2N₂(g) + 6H₂O(g) + 1531 kJ The concentrations of the reactants would decrease after ammonia was added to the system.

When the reaction 2O₃(g) ⇌ 3O₂(g), for which K_p = 3.0 * 10²⁶ at 773ºC, is at equilibrium, the mixture will contain very little O₂ as compared to O₃.

The equilibrium constant for the chemical equation 2NO(g) + O₂(g) ⇌ 2NO₂(g) is two times the equilibrium constant for the chemical equation NO(g) + ¹/₂O₂(g) ⇌ NO₂(g).

For the reaction H₂(g) + I₂(g) ⇌ 2HI(g), K_P = K_c.

Consider the following equilibrium: 4NH₃(g) + 3O₂(g) ⇌ 2N₂(g) + 6H₂O(g) + 1531 kJ The concentrations of the reactants will increase when the temperature is increased.

Equilibrium constants are known for the following reactions: S(s) + ³/₂O₂(g) ⇌ SO₃(g) K_c = 9.2 * 10²³ SO₃(g) ⇌ SO₂(g) + ¹/₂O₂(g) K_c = 4.8 * 10^{- 4} Thus, for the reaction S(s) + O₂(g) ⇌ SO₂(g), K_c = 4.4 * 10²⁰.

Consider the following equilibrium: 4NH₃(g) + 3O₂(g) ⇌ 2N₂(g) + 6H₂O(g) + 1531 kJ The concentrations of the products will increase when the temperature is increased.

The K_c for the reaction CO₂(g) + H₂(g) ⇌ H₂O(g) + CO(g) is 1.6 at about 990ºC. Calculate the number of moles of water in the final equilibrium system obtained by initially adding 1.00 mol of H₂, 2.00 mol of CO₂, 0.750 mol of H₂O, and 1.00 mol of CO to a 5.00 L reactor at 990ºC.

Consider the equilibrium equation C(s) + H₂O(g) ⇌ CO(g) + H₂(g), $\Delta$ H = 2296 J. The reaction will shift towards products if the volume of the container is decreased.

Consider the following equilibrium: 4NH₃(g) + 3O₂(g) ⇌ 2N₂(g) + 6H₂O(g) + 1531 kJ The concentrations the reactants would increase after nitrogen gas was removed from the system.