[guysela31]

How do I calculate pH of water after adding K2CO3?
For example:
Initial water data: pH 6.8, HCO3 100 ppm (so we can calculate the H2CO3 concentration).
To this water I add 100 mg/l of K2CO3. What would be the water pH?

I want to use the equation:
pH= 6.37+log (HCO3/H2CO3) or pH=10.33+log (CO3/HCO3).
The problem is that some (or most) of the CO3 added by K2CO3
converts to HCO3, but I don't know in what proportion.

Thank you

[Borek]

Hydrolysis of a weak acid salt - calculate assuming CO₃^2- is a conjugate base.

But I am not sure if the approach you propose is correct (I can be wrong, it is just intuition telling me to be cautious). Try and show what you get and we will analyze the final result.