I really am struggling with a titration curve problem. It’s a titration of H2A with NaOH. I wish I could post a photo to show it but I don’t know how. Essentially it starts at a ph of 2 then goes up a little (call that A) to equivalence point B at ph of 5 then it goes up a little more (call that C) to equivalence point D at ph 10 then it goes up a little more (call that E). The problem is wanting to know what the major species is affecting each point (A-E) and an equation to show it. I understand that this is a polyprotic acid and that it will go from H2A to HA- to just A- but I don’t understand it all together.

Thank you!!