What mass of NaCl is needed to make 2.50 L of a 2.20 M of a NaCl Solution?

1 Answer
Stefan V.
Mar 4, 2018

#"321 g"#

Explanation:

All you need to know here is that the molarity of a solution tells you the number of moles of solute present in exactly #"1 L"# of the solution.

In your case, a #"2.20-M"# sodium chloride solution will contain #2.20# moles of sodium chloride, the solute, for every #"1 L"# of the solution.

So if every #"1 L"# of this solution must contain #2.20# moles of sodium chloride in order for the solution to have a molarity of #"2.20 M"#, it means that #"2.50 L"# of this solution must contain

#2.50 color(red)(cancel(color(black)("L solution"))) * "2.20 moles NaCl"/(1color(red)(cancel(color(black)("L solution")))) = "5.50 moles NaCl"#

To convert the number of moles of sodium chloride to grams, use the molar mass of the compound.

#5.50 color(red)(cancel(color(black)("moles NaCl"))) * "58.4 g"/(1color(red)(cancel(color(black)("mole NaCl")))) = color(darkgreen)(ul(color(black)("321 g")))#

The answer is rounded to three sig figs.

Related questions
See all questions in Molarity
Impact of this question
14286 views around the world
You can reuse this answer
Creative Commons License