Finding normality, chemistry question, need help please!

I've been stuck on this problem for 4 hours and i don't know what to do.

H3PO4+3NaOH----> Na3PO4+3H2O

if 30.00ml of 0.1000N NaOH was required to neutralize 15.00ml of an H3PO4 solution, what is the normality of the acid? How many grams of H3PO4 are in the 15ml solution?

thank you for your help

WEll its not tht difficult .......

milliequivalents of NaOH = Milli equivalents of H3PO4

Normality of NaOH x Volume of NaoH = N X volume of H3PO4

.1 X 30 = 15N

=> N = .2

Molarity = N / basicity = .2 /3 = 0.067

Also , Molarity = number of moles / Volume

0.067 = n / .15

n = .15 X 0.067 = .01

w / M = .01 M = molar mass = 98 gm/mole


=> w = 0.01 X 98 = 0.98 gms




hope tht helps !! Gud luck !!!:D