If 300 of a NaOH solution are required to neutralize 50 mL of a 6 M H3PO4 solution, what is the concentration of the NaOH solution?

Answer 1

First, we want to write the balanced equation:

H₃PO₄ + 3NaOH → Na₃PO₄ + 3H₂O

Next, we want to find out how many moles of acid have been neutralized.

50mL * (1L / 1000mL) * (6 moles H₃PO₄ / 1L) = 0.3 moles H₃PO₄

Now, using the balanced equation, we can find out how many moles of NaOH are required to neutralize 0.3 moles of H₃PO₄ :

0.3 moles H₃PO₄ * (3 moles NaOH / 1 mole H₃PO₄) = 0.9 moles of NaOH

To get the concentration, we need to take the number of moles of NaOH that were needed to neutralize the acid and divide it by the volume of NaOH that was used for the neutralization. This will give us our concentration.

300mL = 0.3 L, so we have:

(0.9 moles NaOH) / (0.3L) = 3(moles/L) = 3M