Answer to Question #72837 in General Chemistry for Lio

Question

Ethanol (C2H5OH) has a measured density of 0.789 g/mL. You need a solution of ethanol with a concentration of 0.5605 M.

The final volume of the solution should be 0.645 L. What volume of ethanol needs to be added to the flask before it is filled with water to its final volume?

Answer 1

Amount of ethanol: 0.645 ∙ 0.5605 = 0.3615 mol
Mass of ethanol: 0.3615 ∙ 46.07 = 16.6543 g
Volume of ethanol: 16.6543 / 0.789 = 21.1 mL
Answer:
21.1 mL