A 25.2 mL sample of phosphoric acid was titrated with 32.0 mL of 0.550 M NaOH solution. What is the concentration of the
sample given the acid-base reaction shown below?
H3PO4 + 3NaOH = Na3PO4 + 3H2O
M

0.233 M

Explanation: (0.550 M)(0.0320 L)= 17.6e-3 mol NaOH

3:1 ratio of NaOH to H3PO4 so divide the moles of NaOH (17.6e-3) by 3. You will get 5.86e-3.

Finally, divide this number (the moles of H3PO4) by the volume (0.252 L) to get 0.233 M

the correct answer is b. a strong acid completely dissociates to its ions when dissolved in water. completely dissociates to and ions. a is incorrect because does not fully ionize to and ions and some remain as the compound . c and d are incorrect because, and do not fall into the category of bronsted lowry acids. a bronsted lowry acid is a proton donor and since both molecules do not have a proton to donate they are not bronsted lowry acids. likewise,   if we use the lewis acid definition, they cannot be acids. a lewis acid is an electron pair acceptor. both and have a complete octet so can not accept any electrons which disqualifies them as acids.