17. Acid and Base Equilibrium

Which of the following diprotic acid would produce the most acidic solution when dissolved?

Determine the pH of 0.115 M Na₂S. Hydrosulfuric acid, H₂S, possesses K_a1 = 1.0 × 10⁻⁷ and K_a2 = 9.1 × 10⁻⁸.

Consider a 0.10 M solution of a weak polyprotic acid (H₂A) with the possible values of Ka₁ and Ka₂ given here.

a. Ka₁ = 1.0 × 10^-4; Ka₂ = 5.0 × 10^-5

Calculate the contributions to [H₃O⁺] from each ionization step. At what point can the contribution of the second step be neglected?

Calculate the [H3O+] and pH of each polyprotic acid solution.

a. 0.125 M H2CO3

Calculate the [H3O+] and pH of each H2SO4 solution. At approximately

what concentration does the x is small approximation

break down?

a. 0.50 M b. 0.10 M c. 0.050 M

Calculate the [H₃O⁺] and pH of each polyprotic acid solution.

b. 0.125 M H₃C₆H₅O₇

The pH of a particular raindrop is 5.6.

(a) Assuming the major species in the raindrop are H2CO3(aq), HCO3-(aq) and CO32- (aq), Calculate the concentrations of these species in the raindrop, assuming the total carbonate concentration is 1.0 * 10-5 M. The appropriate Ka values are given in Table 16.3.

(b) What experiments could you do to test the hypothesis that the rain also contains sulfur-containing species that contribute to its pH? Assume you have a large sample of rain to test.