A diprotic acid is an acid that can donate two hydronium ions (H+).
Since a diprotic acid has two acidic hydrogens it would have 2 equilibrium equations.
Concept: Diprotic Acids Concept 14m
The diprotic bases would also have 2 equilibrium equations.
Concept: Diprotic Acids Concept 23m
Concept: As a result of these equations for diprotic acids and bases the relationship between Ka and Kb can be established.5m
Concept: Sulfurous acid, H2SO3, represents a diprotic acid with a Ka1 = 1.6 x 10-2 and Ka2 = 4.6 x 10-5. Calculate the pH and concentrations of H2SO3, HSO3– and SO32– when given 0.250 M H2SO3.14m
Concept: Determine the pH of 0.115 M Na2S. Hydrosulfuric acid, H2S, contains Ka1 = 1.0 x 10-7 and Ka2 = 9.1 x 10-8.7m
What is the pH of a 0.310 M solution of H2SO4? Ka2 = 1.20 x 10^-2
Write chemical equations and corresponding equilibrium expressions for each of the two ionization steps of carbonic acid.
Express as chemical equation; identify all phases.
a. Write chemical equations for first ionization step of carbonic acid.
b. Write chemical equations for second ionization step of carbonic acid.
For the diprotic weak acid H2A, Ka1 = 3.1 X 10-6 and Ka2 = 5.1 X 10-9. What is the pH of a 0.0500 M solution of H2A? What are the equilibrium concentrations of H2A and A2- in this solution?
pH = ?
H2A = ?
A2- = ?
Calculate the equilibrium concentration of C2O42− in a 0.20 M solution of oxalic acid.
Express your answer to two significant figures and include the appropriate units.
The pKa's for carbonic acid and bicarbonate at 37°C are 3.83 and 10.25, respectively. Write the equation for each of these equilibria.
H2CO3 is a diprotic acid. The pKa for H2CO3 is 6.35 and the pKa for HCO3- = 10.33. At pH = 9.0, what is the approximate relative quantities of H2CO3, HCO3-, and CO32-?
a. 1 H2CO3, 10 HCO3-, and 1 CO32-
b. Negligible H2CO3, 95 HCO3-, and 5 CO32-
c. 1 H2CO3, 90 HCO3-, and 10 CO32-
d. Negligible H2CO3, 75 HCO3-, and 25 CO32-
Calculate the concentration of H+ ions in a 0.010 M aqueous solution of sulfuric acid.
Express your answer to three decimal places and include the appropriate units.
Identify the weak diprotic acid.