Question

The IR spectrum of a sample contains absorptions at 3050, 2950, and 1620 cm^-1. To what class of organic compound does this sample most likely belong? A) alkane B) alkene C) alkyne D) ester E) alcohol Which of the following most closely matches the C C stretching frequency? A) 3300 B) 3000 C) 2200 D) 1700 E) 1200 What IR absorption is characteristic of the terminal C-H stretch in terminal alkynes? A) 3500 cm^-1 B) 3300 cm^-1 C) 2400 cm^-1 D) 2250 cm^-1 E) 1710 cm^-1 Which compound has a strong and broad IR absorption centered at 3400 cm^-1? A) 1-butanol B) octane C) diethyl ether D) 2-hexyne E) benzene Which compound lacks a strong, characteristic IR absorption near 1700 cm^-1? A) CH_3CH_2CO_2H B) CH_3CH_2CHO C) (CH_3CH_2)_2 C = O D) (CH_3CH_2)_2O E) H_3CH_2CO_2CH_3 Which compound would be expected to show intense IR absorption at 2820, 2710 and 1705 cm^-1? A) CH_3COCH_2CH_3 B) PhCOCH_3 C) PhCHO D) CH_2 CHCOCH_3 Which of the following molecules would have the highest frequency carbonyl stretch? A) (CH_3CH_2)_2CO B) CH_3CH_2CH_2CHO C) CH_3CH_2CO_2CH_3 D) CH_3CH_2CH_2CO_2H E) CH_3CH_2CH_2CONH_2 30) Rank the following bonds in order of increasing stretching frequency (cm-1) in IR spectroscopy: O-H, C N, C-N, and C = O.

Answer 1