Question #620d2
1 Answer
Explanation:
Start by writing the balanced chemical equation that describes this double replacement reaction
#color(blue)(3)"AgNO"_ (3(aq)) + "K"_ 3"PO"_ (4(aq)) -> "Ag"_ 3"PO"_ (4(s)) darr + 3"KNO"_ (3(aq))#
Notice that the reaction consumes
This tells you that in order for all the moles of potassium phosphate to react, you need to ensure that you get at least
Now, you know that molarity represents the number of moles of solute present in
Since
#25.0 color(red)(cancel(color(black)("mL"))) * "1 L"/(10^3color(red)(cancel(color(black)("mL")))) = 1/40# #"L"#
you can say that the potassium phosphate solution contains
#overbrace("0.50 moles K"_3"PO"_4)^(color(purple)("what you have in 1 L of solution")) * 1/40 = 0.05/4# #"moles K"_3"PO"_4#
This means that the silver nitrate solution must contain
#0.05/4 color(red)(cancel(color(black)("moles K"_3"PO"_4))) * (color(blue)(3)"moles AgNO"_3)/(1color(red)(cancel(color(black)("mole K"_3"PO"_4)))) = 0.15/4# #"moles AgNO"_3#
The silver nitrate solution has a molarity of
Since
#(0.15/4color(red)(cancel(color(black)("moles AgNO"_3))))/(0.20color(red)(cancel(color(black)("moles AgNO"_3)))) = 3/16#
it follows that you will need a volume that is
Therefore, you can say that you will need
#3/16 * 1 color(red)(cancel(color(black)("L"))) * (10^3color(white)(.)"mL")/(1color(red)(cancel(color(black)("L")))) = "187.5 mL"#
of
Rounded to two sig figs, the number of sig figs you have for the molarities of the two solutions, the answer will be
#color(darkgreen)(ul(color(black)("volume of AgNO"_3 = "190 mL")))#