Question #0ac55

1 Answer
Mar 18, 2017

Answer:

#"1.4 L"#

Explanation:

For a given solution, we use molarity to express the number of moles of solute present for every #"1 L"# of solution.

In this case, a #"2.8-M"# solution must contain #2.8# moles of solute for every #"1 L"# of solution.

Now, solutions are homogeneous mixtures, which implies that they have the same composition throughout. Consequently, you can say that #4.00# moles of solute in an unknown volume of solution must be equivalent to #2.8# moles of solute in #"1 L"# of solution.

In other words, you can use the molarity of the solution as a conversion factor to determine the volume of the solution that must contain #4.00# moles in order to have a solution that would contain #2.8# moles of solute in #"1 L"# of solution

#4.00 color(red)(cancel(color(black)("moles solute"))) * "1 L solution"/(2.8color(red)(cancel(color(black)("moles solute")))) = color(darkgreen)(ul(color(black)("1.4 L solution")))#

The answer is rounded to two sig figs, the number of sig figs you have for the molarity of the solution.