How can molarity be converted to normality?

How do you determine the normal concentration of a 0.136 M solution of phosphoric acid- assume all of the hydrogens are to be neutralized? Matt (Snosk8311@aol.com)

For acids involved in neutralization reactions, the number of hydrogen ions produced per mole of acid gives the number of equivalents per mole. If all of the hydrogens in phosphoric acid are neutralized, there are three equivalents per mole. Normality is defined as equivalents per liter. So you have a simple unit conversion to do:

0.136 mol H₃PO₄/L

3 equiv = 1 mol

? equiv/L

Note that it's possible to have 1 equiv/mol or 2 equiv/mol for other neutralization reactions involving phosphoric acid if not all of the hydrogens get neutralized-

Author: Fred Senese senese@antoine.frostburg.edu

General Chemistry Online! How can molarity be converted to normality?