Question

Calculate the concentrations of all species in a 0.230-M solution of H₂X if K₁ = 3.16E-05 and K₂ = 2.40E-08

[H₂X] = .230

  M

[H₃O¹⁺] =

M

[HX^1-] =

M

[X^2-] =

M

Answer 1

H2x -----------------> HX-   +    H+

0.230                           0            0

0.230 - x                      x             x

Ka1 = [HX-][H+] / [H2X]

3.16 x 10^-5 = x^2 / 0.230 - x

x = 2.68 x 10^-3

[H3O+] = 2.68 x 10^-3 M

[HX-] =2.68 x 10^-3 M

[X2-] = Ka2 = 2.40 × 10^-8 M