Final answer:
To find the H3O+ concentration and pH of a hydrofluoric acid solution, calculate the concentration of H3O+ using the Ka value and the given concentration of hydrofluoric acid. Then, use the concentration of H3O+ to determine the pH of the solution.
Step-by-step explanation:
The concentration of H3O+ in a solution can be calculated using the given values of pKa1 and pKa2. The concentration of H3O+ can be determined by using the Ka values, which are the equilibrium constants of the acid dissociation reactions:
1. Acid dissociation:
H2C2O4(aq) + H2O(l) ⇌ H3O+(aq) + HC2O4-(aq)
The Ka1 value is calculated by taking the antilogarithm of pKa1: Ka1 = 10^(pKa1)
Using this value, we can calculate [H3O+] as follows:
[H3O+] = sqrt(Ka1 x C)
2. Second acid dissociation:
HC2O4-(aq) + H2O(l) ⇌ H3O+(aq) + C2O4²-(aq)
The Ka2 value is calculated by taking the antilogarithm of pKa2: Ka2 = 10^(pKa2)
Using this value, we can calculate [H3O+] as follows:
[H3O+] = sqrt(Ka2 x C)
By substituting the given concentration of oxalic acid, C = 0.3 M, into the equations, we can find the concentrations of H3O+ and determine the pH accordingly.