How many moles of phosphoric acid are needed to neutralize 5.0 moles of sodium hydroxide?
The balanced chemical equation for the neutralization reaction between phosphoric acid (H3PO4) and sodium hydroxide (NaOH) is:
H3PO4 + 3NaOH --> Na3PO4 + 3H2O
This equation shows that 1 mole of phosphoric acid reacts with 3 moles of sodium hydroxide.
If we have 5.0 moles of sodium hydroxide, we would need 5.0/3 = 1.67 moles of phosphoric acid to completely neutralize it.
Therefore, 1.67 moles of phosphoric acid are needed to neutralize 5.0 moles of sodium hydroxide.