Because carbonic acid undergoes a second ionization, the student in Exercise 12.39 is concerned that the hydrogen ion concentration she calculated is not correct. She looks up the equilibrium constant for the reaction

Upon finding that the equilibrium constant for this reaction is 4.8 × 10^–11, she decides that her answer in Exercise 12.39 is correct. Explain her reasoning.

Data from exercise 12.39

A student is simulating the carbonic acid–hydrogen carbonate equilibrium in a lake:

She starts with 0.1000 M carbonic acid. What are the concentrations of all species at equilibrium?

Transcribed Image Text:

HCO3(aq) H+ (aq) + CO3²- (aq)