For starters, you know that you have
#"HNO"_ (3(aq)) + "KOH"_ ((aq)) -> "KNO"_ (3(aq)) + "H"_ 2"O"_ ((l))#
The two reactants react in a
Now, you're adding
Notice that the volume of the sodium hydroxide solution is double that of the nitric acid solution, but that its concentration is half that of the nitric acid solution.
This should let you know what you're adding equal numbers of moles of the two reactants.
#"1 M" = color(red)(2) xx "0.5 M"#
By doubling the volume of the potassium hydroxide solution, you're ensuring that the number of moles of potassium hydroxide is equal to the number of moles of nitric acid.
You can thus say that the two reactants will be completely consumed by the reaction