Aamc cbt 11 bs 123

[sudo]

In thin-layer chromatography using silica gel plates, the analytes can interact with the silica gel through hydrogen bonding. Which of the following classes of compounds would most likely have the strongest interactions with silica gel?

A) Alcohols
B) Carboxylic Acids
C) Esters
D) Ketones

Correct Answer: B

My approach:
C and D don't have H-bonding, so immediately rule them out. Between A and B...really don't know why it's not alcohols. The explanation said something about carboxylic acids having a more acidic H, but I couldn't make much sense of that.

Can anyone help explain this please? MedPR?

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[CodeRedDew]

The same question was asked a few days ago.

http://forums.studentdoctor.net/showthread.php?t=917540

Essentially, the fact that the carboxylic acid contains a more acidic proton means that there is a larger dipole between the O-H bond in comparison to the alcohol's hydroxyl group (The O has a greater delta- and the H has a greater delta+). This could account for the fact that it makes it a better hydrogen bonding compound as a larger dipole equates to a slightly larger separation of charge, ultimately leading to a stronger hydrogen bond. It could also be due to the fact that there are two positions where hydrogen bonding could occur on the carboxylic acid vs. just one position on the alcohol.