You're mixing hydrochloric acid,
In other words, you need to add enough acid to make sure that the base is completely neutralized.
The balanced chemical equation that describes this neutralization reaction looks like this
#"HCl"_ ((aq)) + "KOH"_ ((aq)) -> "KCl"_ ((aq)) + "H"_ 2"O"_ ((l))#
Notice that you need
Now, you know that you the potassium hydroxide solution has a volume of
Even without doing any calculations, you should be able to say that in order to get a solution of pH equal to
As you can see, both solutions have the same molarity. This implies that equal volumes of these two solutions will contain the same number of moles of solute.
Therefore, you can say that the volume of
#color(green)(|bar(ul(color(white)(a/a)color(black)("volume of HCl " = " 100 mL")color(white)(a/a)|)))#