CHEM 233/CHEM233 C001 Winter 2025/26 - APEI | CHEM233 Week 7 Quiz; Attempt Score 100 / 100 - 100 %.

CHEM 233/CHEM233 C001 Winter 2025/26 - APEI | CHEM233 Week 7 Quiz; Attempt Score 100 / 100 - 100 %. Lesson 7 Quiz - Results Attempt 1 of 1 Written Jun 20, 2025 5:12 PM - Jun 20, 2025 5:33 PM Released Jun 20, 2025 11:59 PM Attempt Score 100 / 100 - 100 % Overall Grade (Highest Attempt) 100 / 100 - 100 % Question 1 4 / 4 points Which of the following does not have a broad absorption with one or more peaks that are centered about 3300 cm-1 in the IR spectrum? 7/13/25, 10:36 PM Tommi-Nikole Gamez - CHEM233 C001 Winter 2025 - APEI 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? Question 3 4 / 4 points An _________ molecular ion peak usually indicates the presence of an odd number of nitrogen atoms in the molecule. (CH3CH2CH2)2NH CH3CH2CH2NH2 (CH3)3CNH2 (CH3CH2CH2)3N (CH2=CHCH2)2NH alkane alkene ester alcohol 7/13/25, 10:36 PM Tommi-Nikole Gamez - CHEM233 C001 Winter 2025 - APEI Which of the following most closely matches the C≡C stretching frequency? Question 5 4 / 4 points Which compound would be expected to show intense IR absorption at 2820, 2710, and 1705 cm-1? odd intense absent weak even 1700 cm-1 3000 cm-1 1200 cm-1 3300 cm-1 2200 cm-1 7/13/25, 10:36 PM Tommi-Nikole Gamez - CHEM233 C001 Winter 2025 - APEI Which of the following has a C-H stretch that occurs at the highest stretching frequency? Question 7 4 / 4 points The two most abundant isotopes of boron are 10B and 11B with 11B being about 4 times more abundant. In the mass spectrum of trimethylborate [(CH3O)3B]: PhCHO PhCOCH3 CH2=CHCOCH3 CH3COCH2CH3 hex-1-ene hexane (E)-hex-2-ene hex-1-yne hex-2-yne 7/13/25, 10:36 PM Tommi-Nikole Gamez - CHEM233 C001 Winter 2025 - APEI Absorption of what type of electromagnetic radiation results in transitions among allowed rotational motions? Question 9 4 / 4 points Which compound would show a larger than usual (M+2) peak in the mass spectrum? the peaks at m/z = 103 and m/z = 104 have equivalent intensities. the peak at m/z = 103 has an intensity which is 4 times the intensity of the peak at m/z = 104. none of these. the peak at m/z = 103 has an intensity which is ¼ the intensity of the peak at m/z = 104. X-rays ultraviolet light microwaves infrared light radio waves 7/13/25, 10:36 PM Tommi-Nikole Gamez - CHEM233 C001 Winter 2025 - APEI Which compound would be expected to show intense IR absorption at 3367 and 3282 cm-1? Question 11 4 / 4 points The mass spectrum of alcohols often fail to exhibit detectable M peaks, but instead show relatively large _________ peaks. CH3(CH2)2CH3 (CH3)2CHNH2 CH3CH2SCH3 CH3CH2CO2H PhCH2NH2 PhCO2H CH3OCH2CH3 but-1-ene 7/13/25, 10:36 PM Tommi-Nikole Gamez - CHEM233 C001 Winter 2025 - APEI Which compound would be expected to show intense IR absorption at 1715 cm-1? Question 13 4 / 4 points Which of the following structures is consistent with the IR spectrum shown below? M+1 M-17 M-18 M-16 M+2 (CH3)2CHCO2H (CH3)2CHNH2 2-methylhexane hex-1-yne 7/13/25, 10:36 PM Tommi-Nikole Gamez - CHEM233 C001 Winter 2025 - APEI 7/13/25, 10:36 PM Tommi-Nikole Gamez - CHEM233 C001 Winter 2025 - APEI Question 15 4 / 4 points Which of the following compounds has the lowest carbonyl stretching frequency? CH3CH2CH2OH 2-methylheptane hex-1-ene CH3CH2COCH3 7/13/25, 10:36 PM Tommi-Nikole Gamez - CHEM233 C001 Winter 2025 - APEI Absorption of what type of electromagnetic radiation results in ionization? 7/13/25, 10:36 PM Tommi-Nikole Gamez - CHEM233 C001 Winter 2025 - APEI Which of the following structures is consistent with the mass spectrum shown below? ultraviolet light infrared light X-rays radio waves microwaves 7/13/25, 10:36 PM Tommi-Nikole Gamez - CHEM233 C001 Winter 2025 - APEI Which compound would be expected to show intense IR absorption at 2250 cm-1? CH3CH2CH2CONH2 (CH3)2CHCH2OH (CH3)2CHCN CH3CH2CH2CO2H 7/13/25, 10:36 PM Tommi-Nikole Gamez - CHEM233 C001 Winter 2025 - APEI Ethyne does not show IR absorption in the cm-1 range because: Question 20 4 / 4 points Absorption of what type of electromagnetic radiation results in transitions among allowed vibrational motions? Question 21 4 / 4 points What effect does conjugation typically have on the frequency at which absorption by C=C occurs? C-H stretches occur at lower energies. there is a change in the dipole moment when the C≡C bond in ethyne stretches. there is no change in the dipole moment when the C≡C bond in ethyne stretches. C≡C stretches occur at about 1640 cm-1. X-rays infrared light radio waves ultraviolet light microwaves 7/13/25, 10:36 PM Tommi-Nikole Gamez - CHEM233 C001 Winter 2025 - APEI Which compound would be expected to show intense IR absorption at 1680 cm-1? Question 23 4 / 4 points Which compound would be expected to show intense IR absorption at 3363, 3185, and 1660 cm-1? Conjugation increases the frequency at which absorption occurs. Conjugation decreases the frequency at which absorption occurs. Conjugation does not affect the frequency at which absorption occurs. none of these 7/13/25, 10:36 PM Tommi-Nikole Gamez - CHEM233 C001 Winter 2025 - APEI When a high energy electron impacts molecule M in the ionization chamber, what type of species is initially produced? Question 25 4 / 4 points In IR spectroscopy, the C-O bond has a _______ frequency than the C-N bond because _______. (CH3)2CHNH2 CH3CH2CONH2 CH3CH2CH2OH but-1-ene a radical cation an anion a radical a cation a radical anion 7/13/25, 10:36 PM Tommi-Nikole Gamez - CHEM233 C001 Winter 2025 - APEI lower, an O atom has more mass than an N atom. lower, an O atom has more electronegativity than an N atom. higher, an O atom has more electronegativity than an N atom. higher, an O atom has more mass than an N atom. higher, an O atom has an even number of neutrons. 7/13/25, 10:36 PM Tommi-Nikole Gamez - CHEM233 C001 Winter 2025 - APEI