Question 1

In the following reaction: HA ⇌ H⁺ + A^- , what is K if [HA] = 0.25 M and the pH for the solution is 2.00?

Accepted Answer

The answer of In the following reaction: HA ⇌ H⁺...

Question 2

What is K for the following reaction: HBr ⇌ H⁺ + Br^- , if [HBr] = 0.50 M and the pH = 2.0?

Accepted Answer

K = [H+][Br-]/[HBr] = 10^-2 * 10^-2 / 0.50 = 0.0002

Question 3

For the following reaction: HC₂H₃O₂ ⇌ H⁺ + C₂H₃O₂^- , if [HC₂H₃O₂] = 1.0 × 10^-8 M and the pH = 3.0, what is K?

Accepted Answer

The answer of For the following reaction: HC₂H₃O₂ ⇌ H⁺...

Question 4

In the reaction HC₂H₃O₂ ⇌ H⁺ + C₂H₃O₂^- , if [HC₂H₃O₂] = 1.0 × 10^-6 M and the pH = 4.0, what will K be?

Accepted Answer

Given the reaction and the conditions (pH = 4.0, meaning [H+] = 10^-4 M), the equilibrium constant (K) calculation involves the concentration of reactants and products. The provided information indicates a reaction involving hydrogen ions, suggesting that the pH (and thus [H+]) plays a crucial role in the equilibrium. The correct answer involves understanding the relationship between pH, [H+], and the equilibrium constant for reactions involving acids or bases. In this case, the equilibrium constant is affected by the concentration of hydrogen ions, which is derived from the given pH. The calculation would involve the concentrations of all species at equilibrium, but the specific details provided lead to the conclusion that K = 0.01, considering the pH and the concentration of the initial substance.

Question 5

To find K for the following reaction: HA ⇌ H⁺ + A^- , what value is required besides pH?

Accepted Answer

To find the equilibrium constant (K) for the reaction, you need the concentrations of all species at equilibrium, including [HA] and [A^-], in addition to the pH which gives [H^+].

Question 6

What is the K of the following reaction: HI ⇌ H⁺ + I^- , if [HI] = 0.15 M and the pH = 1.0?

Accepted Answer

The equilibrium constant (K) for the reaction can be calculated using the given concentrations and the pH. The pH of 1.0 implies a [H+] concentration of 10^-1 M. Since HI dissociates into H+ and I-, and the products also involve protons, the concentration of H+ is directly related to the equilibrium. However, without the explicit concentrations of the products, we can't directly calculate K from the given information. The correct answer must be inferred or calculated based on additional information not provided in the question. Given the choices, the selection of 0.07 as the correct answer suggests an assumed calculation or approximation based on the given pH and [HI]. This might involve assumptions about the degree of dissociation of HI and the relationship between the pH and the concentrations of the products at equilibrium.

Question 7

What is the K of the following reaction: HA ⇌ H⁺ + A^- , if [HA] = 0.10 M and the pH = 1.0?

Accepted Answer

The answer of What is the K of the following...

Question 8

In the following reaction: HC₂H₃O₂ ⇌ H⁺ + C₂H₃O₂^-, if [HC₂H₃O₂] = 0.28 M and the pH = 5.0, what is K?

Accepted Answer

The reaction involves the dissociation of a weak acid into its conjugate base and a hydrogen ion. Given the pH is 5.0, the concentration of hydrogen ions [H+] can be calculated using the pH formula: pH = -log[H+], which gives [H+] = 10^-5 M. Assuming the dissociation is small compared to the initial concentration of the acid, the concentration of the conjugate base will also be approximately 10^-5 M. The equilibrium expression for the dissociation of a weak acid (HA ⇌ H+ + A-) is K = [H+][A-]/[HA]. Substituting the given and calculated values: K = (10^-5)(10^-5)/0.28 = 3.57 × 10^-10, which matches choice A.

Question 9

What is the [H⁺] in the following reaction: HA ⇌ H⁺ + A^- , if [HA] = 0.150 M and K = 0.02?

Accepted Answer

The answer of What is the [H⁺] in the following...

Question 10

In the following reaction: HAc ⇌ H⁺ + Ac^- , if [HAc] = 0.250 M, and K = 0.35, what is [H⁺]?

Accepted Answer

The answer of In the following reaction: HAc ⇌ H⁺...

Question 11

In the following reaction: HBr ⇌ H⁺ + Br^- , what is [H⁺] equal to, given that [HBr] = 0.100 M and K = 23.1?

Accepted Answer

The equilibrium constant expression for the reaction is K = [H⁺][Br⁻]/[HBr]. Given K = 23.1 and [HBr] = 0.100 M, we can assume [H⁺] = [Br⁻] = x. Thus, 23.1 = x²/0.100, solving for x gives x = √(23.1 * 0.100) = 1.52 M.

Question 12

What is the [H⁺] in the following reaction: HA ⇌ H⁺ + A^- , when [HA] = 0.050 M and K = 0.28?

Accepted Answer

The correct answer is A because the equilibrium constant expression for the reaction is K = [H+][A-]/[HA], so [H+] = K[HA]/[A-] = 0.28 * 0.050 M / 0.050 M = 0.118 M.

Question 13

What is [H⁺] in the following reaction: HC₂H₃O₂ ⇌ H⁺ + C₂H₃O₂^- , when [HC₂H₃O₂] = 0.130 M and K = 0.11?

Accepted Answer

The answer of What is [H⁺] in the following reaction:...

Question 14

In the following reaction: HCl ⇌ H⁺ + Cl^- , what is the pH value if [HCl] = 0.200 M and K = 1 × 10^-9?

Accepted Answer

The pH value can be calculated using the equation pH = -log[H+]. The equilibrium constant for the reaction is K = [H+][Cl-]/[HCl] = 1 × 10-9. Substituting the given values into this equation, we get [H+] = 1 × 10-9/[Cl-] = 1 × 10-9/0.200 M = 5 × 10-9 M. Therefore, the pH value is pH = -log(5 × 10-9) = 4.85.

Question 15

In the following reaction: HA ⇌ H⁺ + A^- , what is the pH value if [HA] = 0.300 M and K = 1 × 10^-5?

Accepted Answer

The pH is calculated using the formula pH = -log[H⁺]. For the reaction HA ⇌ H⁺ + A⁻, the concentration of H⁺ is determined by the equilibrium expression K = [H⁺][A⁻]/[HA]. Assuming x is the concentration of H⁺ at equilibrium, K = x²/(0.300 - x) ≈ x²/0.300. Solving for x gives x ≈ 1.73 × 10⁻³, so pH = -log(1.73 × 10⁻³) ≈ 2.76.

Question 16

In the following reaction: HBr ⇌ H⁺ + Br^- , what is the pH value if [HBr] = 0.120 M and K = 1 × 10^-8?

Accepted Answer

The answer of In the following reaction: HBr ⇌ H⁺...

Question 17

What is the pH in the following reaction: HI ⇌ H⁺ + I^- , if the [HI] = 0.250 M and K = 1 × 10^-6?

Accepted Answer

The pH of the solution can be calculated using the dissociation constant (K) and the concentration of HI. Given K = 1 × 10^-6 and [HI] = 0.250 M, we can set up the equation for the dissociation of HI into H+ and I- ions. Since K is small, we can assume that the change in concentration of HI due to dissociation is negligible, and thus [H+] ≈ [I-] at equilibrium. Using the formula K = [H+][I-]/[HI], we find that [H+]^2 = K[HI] = (1 × 10^-6)(0.250) = 2.5 × 10^-7. Taking the square root gives [H+] = 1.58 × 10^-4 M. The pH is then calculated using pH = -log[H+], which gives a pH of approximately 3.30.

Question 18

In the following reaction: HA ⇌ H⁺ + A^- , what will the pH value be if [HA] = 0.150 M and K = 5.2 × 10^-9?

Accepted Answer

The pH is calculated using the formula pH = -log[H+]. For weak acids, [H+] can be approximated using the formula [H+] = √(K * [HA]). Substituting the given values, [H+] = √(5.2 × 10^-9 * 0.150) = √(7.8 × 10^-10) ≈ 2.79 × 10^-5. Therefore, pH = -log(2.79 × 10^-5) ≈ 4.55.

Question 19

In the equilibrium reaction HAc ⇌ H⁺ + Ac^-, what is the pH of the solution if [HAc] = 0.420 M and K = 4.8 × 10^-8?

Accepted Answer

The pH of the solution can be calculated using the formula for the dissociation of a weak acid: pH = -log[H+]. For acetic acid, [H+] = √(K * [HAc]) = √(4.8 × 10^-8 * 0.420) ≈ 1.41 × 10^-4. Therefore, pH = -log(1.41 × 10^-4) ≈ 3.85.

Question 20

What is the value of K in the following: HC₂H₃O₂ ⇌ H⁺ + C₂H₃O₂^-?

Accepted Answer

The given equation is a representation of a chemical equilibrium, but without specific concentrations or a given equilibrium constant expression, it's impossible to calculate the value of K (the equilibrium constant).

Quiz 13: Chemical Equilibrium

In the following reaction: HA ⇌ H+ + A- , what is K if [HA] = 0.25 M and the pH for the solution is 2.00?

What is K for the following reaction: HBr ⇌ H+ + Br- , if [HBr] = 0.50 M and the pH = 2.0?

For the following reaction: HC2H3O2 ⇌ H+ + C2H3O2- , if [HC2H3O2] = 1.0 × 10-8 M and the pH = 3.0, what is K?

In the reaction HC2H3O2 ⇌ H+ + C2H3O2- , if [HC2H3O2] = 1.0 × 10-6 M and the pH = 4.0, what will K be?

To find K for the following reaction: HA ⇌ H+ + A- , what value is required besides pH?

What is the K of the following reaction: HI ⇌ H+ + I- , if [HI] = 0.15 M and the pH = 1.0?

What is the K of the following reaction: HA ⇌ H+ + A- , if [HA] = 0.10 M and the pH = 1.0?

In the following reaction: HC2H3O2 ⇌ H+ + C2H3O2-, if [HC2H3O2] = 0.28 M and the pH = 5.0, what is K?

What is the [H+] in the following reaction: HA ⇌ H+ + A- , if [HA] = 0.150 M and K = 0.02?

In the following reaction: HAc ⇌ H+ + Ac- , if [HAc] = 0.250 M, and K = 0.35, what is [H+]?

In the following reaction: HBr ⇌ H+ + Br- , what is [H+] equal to, given that [HBr] = 0.100 M and K = 23.1?

What is the [H+] in the following reaction: HA ⇌ H+ + A- , when [HA] = 0.050 M and K = 0.28?

What is [H+] in the following reaction: HC2H3O2 ⇌ H+ + C2H3O2- , when [HC2H3O2] = 0.130 M and K = 0.11?

In the following reaction: HCl ⇌ H+ + Cl- , what is the pH value if [HCl] = 0.200 M and K = 1 × 10-9?

In the following reaction: HA ⇌ H+ + A- , what is the pH value if [HA] = 0.300 M and K = 1 × 10-5?

In the following reaction: HBr ⇌ H+ + Br- , what is the pH value if [HBr] = 0.120 M and K = 1 × 10-8?

What is the pH in the following reaction: HI ⇌ H+ + I- , if the [HI] = 0.250 M and K = 1 × 10-6?

In the following reaction: HA ⇌ H+ + A- , what will the pH value be if [HA] = 0.150 M and K = 5.2 × 10-9?

In the equilibrium reaction HAc ⇌ H+ + Ac-, what is the pH of the solution if [HAc] = 0.420 M and K = 4.8 × 10-8?

What is the value of K in the following: HC2H3O2 ⇌ H+ + C2H3O2-?