A 40-mM KCl solution is used to treat patients with low potassium levels. How many moles of KCl are present in 2.00 liters of this solution? How many grams of KCl are present? Thanks in advance

1 Answer
Apr 7, 2018

#"80 mmol"# and #"5.96 g"#

Explanation:

#"Molarity" = "Moles of solute"/"Volume of solution (in litres)"#

#40 × 10^-3\ "M" = "n" / "2.00 L"#

#"n" = 40 × 10^-3\ "M" × "2.00 L" = 80 × 10^-3\ "mol" = color(blue)"80 mmol"#

#underline(color(white)(.jdjddhhhhhhh))#

Molar mass of #"KCl"# is #"74.5 g/mol"#

Mass of #"80 mmol"# of #"KCl"# is

#80 × 10^-3 cancel"mol" × 74.5 "g"/cancel"mol" = color(blue)"5.96 g"#