A 10.0 mL sample of a monoprotic acid is titrated with 45.5 mL of 0.200 M #NaOH#. What is the concentration of the acid?
A monoprotic acid can contribute one proton to the neutralization reaction that takes place when sodium hydroxide,
If you take
#"HA"_ ((aq)) + "NaOH"_ ((aq)) -> "NaA"_ ((aq)) + "H"_ 2"O"_ ((l))#
Iin order to have a complete neutralization, you need to add equal numbers of acid and of base.
Now, let's assume that the monoprotic acid solution has a molarity equal to
However, you know that the acid solution has a volume of
#(45.5 color(red)(cancel(color(black)("mL"))))/(10.0 color(red)(cancel(color(black)("mL")))) = color(blue)(4.55)#
smaller than what you'd need if the acid solution had the same molarity as the sodium hydroxide solution. This can only mean that the acid solution is
You thus have
#c_("HA") = color(blue)(4.55) * "0.200 M" = color(green)(|bar(ul(color(white)(a/a)color(black)("0.910 M")color(white)(a/a)|)))#
Therefore, you can say for a fact that