How do you calculate the grams solute required to make the following solution: 2.5 L of 0.90% of NaCl (m/v)?

1 Answer
May 13, 2017

Answer:

Here's how you can do that.

Explanation:

You know that a solution's mass by volume percent concentration, #"% m/v"#, tells you the number of grams of solute present for every #"100 mL"# of solution.

This implies that a #"0.90% m/v"# solution will contain #"0.90 g"# of sodium chloride, the solute, for every #"100 mL"# of solution.

You can thus say that

#2.5 color(red)(cancel(color(black)("L"))) * (10^3color(white)(.)"mL")/(1color(red)(cancel(color(black)("L")))) = 2.5 * 10^3# #"mL"#

of #"0.90% m/v"# sodium chloride solution must contain

#2.5 * 10^3 color(red)(cancel(color(black)("mL solution"))) * "0.90 g NaCl"/(100color(red)(cancel(color(black)("mL solution"))))= color(darkgreen)(ul(color(black)("23 g NaCl")))#

The answer is rounded to two sig figs.