Answer:
NaOH
Explanation:
The limiting reactant is the reactant in short supply in an experiment.
We have been given:
Number of moles of H₃PO₄ = 1.75mle
Now from the balanced reaction equation:
1 mole of H₃PO₄ will require 3 moles of NaOH to react with
1.75 mole of H₃PO₄ will then require 1.75 x 3 = 5.25mole of NaOH
But the given amount of NaOH is 5mole, so NaOH is the limiting reactant.