Example: In 1 liter pure water add 0.01 mol of hydrochloric acid. Calculate this solution's ph change value. And in 1 liter contain 0.1 mol acetic acid and 0. acetate ion mixture solution add 0.01mol of hydrochloric acid. Calculate this solution ph change value. Notice: Square bracket will instead of equilibrium concentration in following time. Such as [H+] instead hydrogen ion equilibrium concentration