Question

The functional groups in an organic compound can frequently be deduced from its infrare d absorption spectrum. A compound, C3H6O2, exhibits intense absorption at 1740 cm-1, accompanied by a band at 1050 cm-1. No absorption above 3000 cm-1 is present .
What functional class(es) does the compound belong to?
List only classes for which evidence is given here. Attach no significance to evidence not cited explicitly.
Do not over-interpret exact absorption band positions. None of your inferences should depend on small differences like 10 to 20 cm-1.
The functional class(es) of this compound is(are) .(Enter letters from the table below, in any order, with no spaces or commas.)
a. alkane (List only if no other functional class applies.)
b. alkene
c. terminal alkyne
d. internal alkyne
e. arene
f. alcohol
g. ether
h. amine
i. aldehyde or ketone
j. carboxylic acid
k. ester
l. nitrile

Answer 1

Answer:

(b.) alkene

(i) aldehyde/ketone

(k.) ester

Explanation:

Peaks observed at:

• 1740 cm-1 indicates the presence of a carbonyl group: C=O aldehyde, ketone, esters.
• 1050 cm-1 shows presence of carbo bonded to electronegative elements e.g. C-N or C-O
• 3000cm-1 is usually indicative of alcohols or carboxylic acid -OH group, which rules out those classes.