What is the molarity of glacial acetic acid (CH3COOH, Mr = 60.05g/mol) at 25 degrees C given that the density of acetic acid at that temperature is 1.049g/mL?
##”17.47 M”##
is defined as moles of per liters of solution.
##color(blue)(c = n/V)##
Glacial acetic acid is actually anhydrous acetic acid, which implies that the acetic acid is not actually dissolved in a and therefore is not ctually a solute.
However, you can still calculate its based on the number of moles of you get per liter of glacial acetic acid.
To do that, start with a sample o ##”1.000 L”## of glacial acetic acid. You know that at ##25^@”C”##, glacial acetic acid has a of ##”1.049 g/mL”##, which tells you that every mililiter of glacial acetic acid has a mass of ##”1.049 g”##.
This means that the mass of the sample will be
##1.000color(red)(cancel(color(black)(“L”))) * (1000color(red)(cancel(color(black)(“mL”))))/(1.000color(red)(cancel(color(black)(“L”)))) * “1.049 g”/(1color(red)(cancel(color(black)(“mL”)))) = “1049 g”##
To find how many moles you get in the sample, use the given molar mass, which tells you how many grams of acetic acid you get per mole
##1049color(red)(cancel(color(black)(“g”))) * (“1 mole CH“_3″COOH”)/(60.05color(red)(cancel(color(black)(“g”)))) = “17.469 moles CH”_3″COOH”##
Now that you know the volume of the sample and how many moles it contains, you can say that
##c = “17.469 moles”/”1.000 L” = color(green)(“17.47 M”)##
I’ll keep the number of given for the density of glacial acetic acid.