Question

In a titration, 50.0 mL of KOH is added to 25.0 mL of 0.15 M H3PO4 until the equivalence point is reached. What is the pH at the equivalence point?

Answer 1

@JoannaBlackwelder

Answer 2

Hm, I`m not too sure about this one. H3PO4 is a triprotic weak acid, so it would have multiple equivalence points. Here is some info about triprotic weak acids. http://chemwiki.ucdavis.edu/Wikitexts/UC_Davis/UCD_Chem_2B/UCD_Chem_2B%3A_Larsen/Unit_III%3A_Acids_and_Bases/16.5%3A_Acid%E2%80%93Base_Titrations
Under Titrations of Polyprotic Acids and Bases

Answer 3

Thanks for giving it a try anyways

Answer 4

No worries. :)

Answer 5

@abb0t

Answer 6

The solution at the first equivalent point will be that of a KH2PO4 solution.

Provided that H2PO4- is an amphoteric substance, the pH is easy to guess.