Question

Ascorbic acid (C6H8O6) has how many acidic protons that it will lose when reacting with NaOH?

Answer 1

Hard to say...

I would say only one (with `K_(a1) = 7.9 xx 10^(-5)`), from looking at its structure... perhaps two if you really cared for a `K_(a2)` of only `1.6 xx 10^(-12)`. If you really slammed it with `"NaOH"`, you would eventually abstract that second proton, but it would take a while.

[Carbonic acid is considered diprotic and its second `K_a` is an order of magnitude larger than the second `K_a` of ascorbic acid.]

More `K_a`s can be found here.