In: Chemistry
What is the ph of 0.10 M Ca(C3H5O3)2?
it is lactic acid salt : lactic acid Ka = 1.4 x 10–4
C3H5O3- + H2O ------------------> C3H5O3H + OH-
0.10 0 0
0.10-x x x
Ka = x^2 / 0.10-x
1.0 x 10^-14 / 1.4 x 10^-4 = x^2 / 0.10-x
7.14 x 10^-11 = x^2 / 0.10-x
x^2 + 7.14 x 10^-11 x - 7.14 x 10^-12 = 0
x = 2.67 x 10^-6
[OH-] = x = 2.67 x 10^-6 M
pOH = -log [OH-]
pOH = - log (2.67 x 10^-6)
pOH = 5.57
pH + pOH = 14
pH = 8.43