Question

A student adds 52.1 grams of ethanol, C2H5OH, to a volumetric flask and fills the

flask with water to the 200.00 mL fill line. What is the molarity of this solution?

Answer 1

Molar mass of ethanol C

2

H

5

OH = 12x2 + 1x6 + 1x16 = 46 g/mol

Mass = moles x molar mass

Mass of ethanol required = 1.2 x 46 = 55.2 g

Volume = mass/density

Volume required = 55.2/0.7893

= 70 ml