Question

Which of the following concentrations would be practically equal in a calculation of the equilibrium concentrations in a 0.134-M solution of (H₂CO₃), a diprotic acid: ([H₃O⁺]), ([OH⁻]), ([HCO₃⁻]), ([CO₃²-])?

a) ([H₃O⁺], [OH⁻])
b) ([H₃O⁺], [HCO₃⁻])
c) ([OH⁻], [CO₃²-])
d) ([HCO₃⁻], [CO₃²-])

Answer 1

In a 0.134-M solution of diprotic acid H₂CO₃ at equilibrium, the concentrations of H₃O⁺ and HCO₃⁻ are both 1.2 × 10⁻⁴ M, which makes them practically equal.

Step-by-step explanation:

In the context of equilibrium concentrations in a 0.134-M solution of H₂CO₃, a diprotic acid, we are looking to compare the concentrations of different species present in solution at equilibrium.

Given the summary provided, we can see that at equilibrium, the concentration of H₃O⁺ is 1.2 × 10⁻⁴ M and the concentration of HCO₃⁻ is also 1.2 × 10⁻⁴ M. Therefore, they have the same concentrations, which answers the question.

Comparing this information, we can deduce that option (b) [H₃O⁺], [HCO₃⁻] represents the species that would have practically equal concentrations in the equilibrium calculation of H₂CO₃ solution.