What is the normality of #0.3 M# of #H_3PO_4#?

1 Answer
May 7, 2018

see below


Normality is a concentration that depends by the reaction that you do, then it can assume different valours, and IUPAC recommende don't use it.
In spite of this, generally #H_3PO_4# is considered an acid and its Normality is like the concentration of #H^+#ions if the compound is completely dissociated, hence it would be triple of molarity = 0,9 M
If you want titrate the acid you never titrate the third hydrogen atom but the first (with indicator orange Methyl) or the second (with indicator Phenolphtaleine) so in these reactions #H_3PO_4# normality would be respectively 0,3 N and 0,6 N