The chemical equation is:
HCO3^ -> H^+ + CO3^2-
We know that the formula
for Ka is:
Ka = [H^+][CO3^2-]/[HCO3^-]
log Ka = log[H^+] + log[CO3^2-]/[HCO3^-]
pKa = pH - log[CO3^2-]/[HCO3^-]
log[CO3^2-]/[HCO3^-] = pH - pKa = 10.75 - 10.329 = 0.421
[CO3^2-]/[HCO3^-] = Antilog (0.421) = 2.636
Answer:
2.636
