Organic Chemistry 1 · Infrared evidence
Predict a diagnostic region
Conditions: Consider a neat liquid sample of the drawn compound; band descriptions are qualitative teaching predictions.
Draw this problem yourself
Drag from the electrons that move to where they go, or tap one and then the other. Every arrow is checked; Hint helps when you're stuck. No account needed.
The question
Which feature is expected for the drawn molecule in addition to its C–H absorptions?
Reveal the answer and explanation
Answer and explanation
Correct answer A broad O–H stretching envelope.
The molecule has an alcohol O–H bond; intermolecular hydrogen bonding broadens its stretch.
Not this one A strong carbonyl stretch.
There is no C=O bond in this molecular structure.
Not this one A sharp nitrile stretch.
There is no C≡N group or nitrogen atom in this structure.
Worked solution
Ethanol has an oxygen bonded to carbon and hydrogen. In a neat sample its molecules hydrogen-bond, creating a distribution of O–H environments and a broad stretching envelope. Neither carbonyl nor nitrile absorption is predicted because those bonds are absent.
What you'll practice
Relate an explicit O–H bond to hydrogen-bonded IR absorption.
You just pushed every arrow of this one.
Every one of the 5349 Orgo 1 and Orgo 2 problems works like this: feedback on each arrow, hints when you're stuck, a no-hint quiz mode. Free with an account, no card.
Stuck on your own homework?
Snap it — first scan free, no sign-up
Scanning every week? Scan Standard: for about problems