In: Chemistry
what is the pH of 0.120 M Fe(NO_3)_3 (Ka of
Fe^3+=3.00x10^-3)? Express your answer to two decimal
places.
[Fe(H2O)6]+3 ---------------> [Fe(H2O)5OH]2+ + H+
0.120 0 0
0.120 - x x x
Ka = x^2 / 0.120 - x
3.00 x 10^-3 = x^2 / 0.120 - x
x = 0.0175
[H+] = 0.0175 M
pH = -log [H+] = -log (0.0175)
pH = 1.76