can someone help me with this assignmentplease dont answer i

can someone help me with this assignment,please dont answer if you arent sure

2. For the following spectra (a-e), there is a choice of three possible compounds for each. For each spectrum, the most appropriate class of compound, and explain your reasoning by characteristic peaks. noting the presence or absence of (10 points) a. Alcohol, carboxylic acid or phenol Reasoning: b. Aldehyde, ester or ketone Reasoning:

Solution

2. The given spectrum

a. Is carboxylic acid

Broad peak between 2500-3200 cm-1 and a carbonyl peak at 1720 cm01

b. Is aldehyde

carbonyl peak at 1720 cm-1 and aldehyde C-H stretch at 2750 cm-1 and 2840 cm-1

c. 1o alkyne

A sharp strong peak at 3300 cm-1 for terminal alkyne C-H stretch

d. primary amine

Two peaks at 3300-3400 cm-1 for two N-H stretch

e. Anhydride

two peaks for carbonyls at 1710 and 1800 cm-1.

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3. Differentiation of compounds by IR

The second spectrum is for the first compound (symmetrical ketone) shows sharp single peak at 1720 cm-1 for C=O stretch

The first spectrum is for the unsymmetrical unsaturated ketone. lower frequency stretch at 1690 cm-1 for C=O stretch and 1610 cm-1 peak for C=C stretch.

4. In symmetrical alkynes, no alkyne C-H are present and thus IR absorption is absent.

5. distinguishing between compounds

a. First : 3350 cm-1 for O-H stretch, 1620 cm-1 for C=C stretch

Second : 1710 cm-1 for C=O stretch

b. First : 2750 cm-1 and 2850 cm-1 for aldehyde C-H stretch

Second : broad peak 2500-3200 cm-1 for O-H of -COOH functionality

c. First : 2250 cm-1 for CN stretch

Second : 3300 sharp peak for terminal alkyne C-H stretch