Question #8fc4f
1 Answer
Here's what I got.
Explanation:
The idea here is that you're trying to figure out how many milliliters of
The balanced chemical equation that describes this neutralization reaction looks like this
#"H"_ 3"PO"_ (4(aq)) + color(blue)(3)"NaOH"_ ((aq)) -> "Na"_ 3"PO"_ (4(aq)) + 3"H"_ 2"O"_ ((l))#
Notice that the reaction consumes
Now, use the molarity and volume of the phosphoric acid solution to determine how many moles of acid were present in the solution
#23.25 color(red)(cancel(color(black)("mL"))) * (1 color(red)(cancel(color(black)("L"))))/(10^3color(red)(cancel(color(black)("mL")))) * ("1.400 moles H"_3"PO"_4)/(1color(red)(cancel(color(black)("L"))))#
# = "0.03255 moles H"_3"PO"_4#
Use the aforementioned mole ratio to figure out how many moles of sodium hydroxide were needed to neutralize all the moles of phosphoric acid
#0.03255 color(red)(cancel(color(black)("moles H"_3"PO"_4))) * (color(blue)(3)color(white)(a)"moles NaOH")/(1color(red)(cancel(color(black)("mole H"_3"PO"_4))))#
# = " 0.09765 moles NaOH"#
Finally, use the molarity of the sodium hydroxide solution to calculate how many milliliters of solution would contain this many moles
#0.09765color(red)(cancel(color(black)("moles NaOH"))) * (1color(red)(cancel(color(black)("L"))))/(1.320color(red)(cancel(color(black)("moles NaOH")))) * (10^3"mL")/(1color(red)(cancel(color(black)("L"))))#
# = color(green)(bar(ul(|color(white)(a/a)color(black)("73.98 mL")color(white)(a/a)|)))#
The answer is rounded to four sig figs.