What is the molarity of the solution produced when #"350.0 mL"# of water and #"75.0 mL"# of #"0.125 M"# #"NaNO"_3# are mixed an boiled down to #"325.0 mL"# ?
1 Answer
Explanation:
The trick here is to realize that the number of moles of sodium nitrate present in the solution does not change.
When you dilute the solution by adding the
Similarly, when you boil the solution, you decrease its volume to
Basically, by diluting and boiling the solution, you're changing its volume without affecting the number of moles of solute it contains.
So, you know that the initial solution contains
#75.0 color(red)(cancel(color(black)("mL solution"))) * "0.125 moles NaNO"_3/(10^3color(red)(cancel(color(black)("mL solution")))) = "0.009375 moles NaNO"_3#
This means that the final solution will contain
#["NaNO"_3] = "0.009375 moles"/(325.0 * 10^(-3) quad "L") = color(darkgreen)(ul(color(black)("0.0288 M")))#
The answer is rounded to three sig figs.