How do you calculate pH diprotic acid?
I would not typically teach this to my high school students, so I looked around and found a great explanation on you tube.
Since, in a polyprotic acid the first hydrogen will dissociate faster than the others, If the Ka values differ by a factor of 10 to the third power or more, it is possible to approximately calculate the pH by using only the Ka of the first hydrogen ion. For example:
for the acid.
If you know the concentration of the of the acid, say it is 0.0027M and the