In: Chemistry
Calculate the pH and the equilibrium concentrations of HCO3- and CO32- in a 0.0514 M carbonic acid solution, H2CO3 (aq). For H2CO3, Ka1 = 4.2×10-7 and Ka2 = 4.8×10-11 pH = [HCO3-] = M [CO32-] = M
H2CO3 (aq) <---------------> H+ (aq) + HCO3- (aq)
0.0514 0 0
0.0514 - x x x
Ka1 = x^2 / 0.0514 - x
4.2 x 10^-7 = x^2 / 0.0514 - x
x = 1.47 x 10^-4
[H+] = 1.47 x 10^-4 M
pH = -log (1.47 x 10^-4)
pH = 3.83
[HCO3-] = 1.47 x 10^-4 M
[CO32-] = 4.80 x 10^-11 M