Question #46fd6
1 Answer
Explanation:
The idea here is that you can convert the solution's concentration from percent concentration by mass, or
To make calculations easier, you can pick a
By definition, a solution's percent concentration by mass is defined as the mass of the solute, in this case methanol, divided by the total mass of the solution, and multiplied by
%m/m=mass of solutemass of solution×100
In your case, the
To get the number of moles of methanol, use the compound's molar mass
0.750g⋅1 mole CH3OH32.042g=0.02341 moles CH3OH
Now, to get the volume of the sample, you need to use its density. A
https://en.wikipedia.org/wiki/Methanol_%28data_page%29
This means that the sample will have a volume of
100g⋅1 mL0.997g=100.3 mL
Molarity is defined as moles of solute per liter of solution
c=nV
In your case, you would get - do not forget to convert the volume from mililiters to liters!
c=0.02341 moles100.3⋅10−3L=0.233 M
The answer is rounded to three sig figs.
