Question

Laszlo is running a column to separate a carboxylic acid and an alkyne. He accidentally uses acetone instead of hexane as his first eluent. What happens? A. The first fraction contains only carboxylic acid and the second fraction contains only alkyne. B. The first fraction contains both the carboxylic acid and the alkyne. C. The fractions are empty because both compounds remain on the column. D. The first fraction contains only alkyne and the second fraction contains only carboxylic acid. E. The first fraction contains only carboxylic acid and the alkyne remains on the column F. The first fraction contains only alkyne and the carboxylic acid remains on the column.

Answer 1

Answer:

B. The first fraction contains both the carboxylic acid and the alkyne.

Explanation:

Carboxylic acids dissolve in both polar and non-polar organic solvents hence they can dissolve in acetone along with the alkyne.

The correct sequence of adding eluting solvents is reversed,  would have been the addition of hexane first in order to elute the alkyne selectively. The acetone may now be subsequently added to elute the carboxylic acid.

If this order the carboxylic acid and alkyne are eluted simultaneously.