Asked by Joseph Wilson on May 06, 2024
Verified
In the following reaction: HC2H3O2 ⇌ H+ + C2H3O2-, if [HC2H3O2] = 0.28 M and the pH = 5.0, what is K?
A) 3.57 × 10-10
B) 1.00 × 10-4
C) 1.00 × 10-10
D) 3.57 × 10-4
pH
A numeric scale used to specify the acidity or basicity (alkalinity) of an aqueous solution, with 7 being neutral, values below 7 acidic, and above 7 basic.
K
The symbol for potassium, a chemical element of atomic number 19, essential for living organisms.
[HCO3-]
The chemical formula for bicarbonate, an anion involved in the buffering of pH in biological systems.
- Identify the correlation between the pH of a solution and the concentrations of reactants and products in cases of acid-base equilibria.
- Examine the role of equilibrium constants in understanding the degree of chemical reactions.
Verified Answer
ZK
Zybrea KnightMay 07, 2024
Final Answer :
A
Explanation :
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.
Learning Objectives
- Identify the correlation between the pH of a solution and the concentrations of reactants and products in cases of acid-base equilibria.
- Examine the role of equilibrium constants in understanding the degree of chemical reactions.