An aqueous solution contains 0.216 M ascorbic acid (H2C6H6O6) and 0.131 M hydrochloric acid.

Calculate the ascorbate (C6H6O62-) ion concentration in this solution.

[C6H6O62-] =______________ mol/L.

Ascorbic acid = HAsc

.........HAsc ==> H^+ + Asc^-
initial.0.216.....0......0
change....-x.......x......x
equil..0.216-x.....x.......x

..........HCl ==>H^+ + Cl^-
initial...0.131..0......0
change...-0.131..0.131..0.131
equiol....0......0.131..0.131

Write the Ka expression for HAsc
K = (H^+)(Asc^-)/(HAsc)
For (H^+) substitute x + 0.131 (x from the HAsc equil + 0.131 from the HCl equil).
For (Asc^-) substitute x
For (HAsc) substitute 0.216-x
Solve for x.

To calculate the concentration of the ascorbate (C6H6O62-) ion in the solution, we need to understand the dissociation reaction of ascorbic acid (H2C6H6O6) and the stoichiometry of the reaction.

The dissociation reaction of ascorbic acid (H2C6H6O6) can be represented as follows:

H2C6H6O6 ⇌ H+ + HC6H6O6-

From the equation, we can see that for every molecule of ascorbic acid that dissociates, we get one ascorbate (C6H6O62-) ion formed. The concentration of the ascorbate ion is, therefore, the same as the concentration of the H2C6H6O6 that dissociated.

Given that the concentration of ascorbic acid (H2C6H6O6) in the solution is 0.216 M, the concentration of the ascorbate (C6H6O62-) ion is also 0.216 M.