A researcher synthesizes isobutyric acid through the oxidation of isobutyl alcohol with potassium permanganate. The reaction was completed in a diethyl either solvent. In order to extract isobutyric acid from the solvent, the researcher should wash the solution with:
a) 1 30mL wash of water
b) 3 10mL washes of water
c) 1 30mL wash of hexane
d) 3 10mL washes of hexane
Click for Explanation
Isobutyric acid has a carboxylic acid group, is polar, and can readily hydrogen bond. It can be extracted from the organic solvent, diethly ether, by washing with water. Multiple smaller volume washer extract better than one large volume wash. Use of a second organic solvent, hexane, will not extract the isobutyric acid from the diethyl ether.
a) 1 30mL wash of water, incorrect, Multiple smaller volume washes will yield higher extraction results.
b) 3 10mL washes of water, correct, Isobutyric acid will enter the aqueous layer and wash off of the organic layer of diethyl ether.
c) 1 30mL wash of hexane, incorrect, Hexane is another organic solvent like diethyl ether.
d) 3 10mL washes of hexane, incorrect, See c).
Want more MCAT practice?
We’ve got options for every schedule and learning style!
Whether you need the flexibility of a Self-Paced Course, the instruction of a live 515+ Course, or the 1:1 attention of a private MCAT tutor, Blueprint MCAT has the MCAT prep option that works for your learning style!
Get started with a free MCAT diagnostic, one free practice exam, and tons more MCAT prep resources.
Not sure which option is right for you? Schedule a free MCAT consultation with an MCAT expert using the form below. No obligation, just expert advice.
