Question #5d0f5

1 Answer
Sep 26, 2015

Answer:

#"0.00553 M"#

Explanation:

All you really have to do here is convert the patient's cholesterol count from miligrams per deciliter to grams per liter, then use cholesterol's molar mass to find its molarity.

So, use the following conversion factors

#"1 g" = "1000 mg" " "# and #" " "1 L" = "10 dL"#

to convert the patient's cholesterol count

#214color(red)(cancel(color(black)("mg")))/(1color(red)(cancel(color(black)("dL")))) * (10color(red)(cancel(color(black)("dL"))))/"1 L" * "1 g"/(1000color(red)(cancel(color(black)("mg")))) = "2.14 g/L"#

Since molarity is defined as moles of solute, in your case cholesterol, per liters of solution, simply use cholesterol's molar mass to get

#2.14color(red)(cancel(color(black)("g")))/"L" * "1 mole"/(386.64color(red)(cancel(color(black)("g")))) = color(green)("0.00553 M")#

If you want, you can express this molar concentration in milimoles per liter, or milimolar

#0.00553color(red)(cancel(color(black)("moles")))/"L" * "1000 mmoles"/(1color(red)(cancel(color(black)("mole")))) = color(green)("5.53 mM")#