Question 1

Examine the IR below and classify the compound.

Accepted Answer

The answer of Examine the IR below and classify the...

Question 2

Which of the following statement(s) is (are) true about a compound that has a molecular ion peak in its mass spectrum at mass 69, and shows a prominent peak in its IR spectrum at 2250 cm^-1?

Accepted Answer

EThe molecular ion peak at mass 69 indicates the molecular mass of the compound is 69, not 70, making statement A incorrect and thus D and E need to be evaluated on the second part of their statements. The IR spectrum peak at 2250 cm^-1 is characteristic of cyano (C≡N) groups or alkynes (C≡C), not C=O groups, which typically absorb around 1700 cm^-1. Therefore, statement C is correct, and since A is incorrect, E is the correct combination statement, indicating the compound has a molecular mass of 69 and contains a cyano or alkyne group.

Question 3

The base peak in a mass spectrum corresponds to the most stable fragment. Propose a structure for a compound that is consistent with the following data. (a) The molecular ion peak has m/z = 116 (b) The base peak is at m/z = 59. (c) The compound is composed of C, H and O atoms. (d) The IR spectrum shows a strong absorbance at 3257 cm^-1.

Accepted Answer

The answer of The base peak in a mass spectrum...

Question 4

Examine the IR below and classify the compound.

Accepted Answer

The IR spectrum shows a strong and broad peak around 3100-3000 cm-1, which corresponds to the aromatic C-H stretch in arenes. No other significant peaks for other functional groups are observed. Therefore, the compound is most likely an arene.

Question 5

What type of signal(s) would you observe in the mass and (or) infrared spectrum of the following compound?

Accepted Answer

The answer of What type of signal(s) would you observe...

Question 6

Examine the IR below and classify the compound.

Accepted Answer

The answer of Examine the IR below and classify the...

Question 7

When the phenol shown below is treated with KOH, it forms a product whose IR spectrum does not show an absorption in the 3200-3600 cm^-1 region. Propose a structure for the product.

Accepted Answer

The answer of When the phenol shown below is treated...

Question 8

In a typical mass spectrum, a smaller signal is observed at a mass 1 amu higher than the molecular ion peak. Why?

Accepted Answer

The mass difference of 1 amu is likely due to the presence of a carbon atom with the isotope ¹³C instead of the more common ¹²C. This small percentage of the compound with the heavier isotope would result in a slightly higher mass peak in the mass spectrum.

Question 9

Which of the following information is primarily obtained from an IR spectrum?

Accepted Answer

An IR spectrum primarily provides information on the functional groups present in a compound, such as the presence of carbonyl, hydroxyl, or amine groups. This information can be used to identify and characterize the compound.

Question 10

An IR spectrum has the following potentially important absorptions: 3091, 3067, 2963, 2921, 2252, 1603, 1499, 1455, 1416, 1078, 1031, 941, 735, and 696 cm^-¹. Indicate which structure corresponds to the IR data.

Accepted Answer

The answer of An IR spectrum has the following potentially...

Question 11

Which of the following compounds will have the lowest wavenumber for carbonyl absorption?

Accepted Answer

The answer of Which of the following compounds will have...

Question 12

Examine the IR below and classify the compound.

Accepted Answer

The IR spectrum of the compound shows a strong peak at around 1715 cm-1, which corresponds to the C=O stretching vibration of a ketone functional group. Therefore, the best choice for the classification of this compound is D) Ketone.

Question 13

What type of signal(s) would you observe in the mass and/or infrared spectrum of the following compound?

Accepted Answer

The answer of What type of signal(s) would you observe...

Question 14

Which of the following structures is consistent with a compound that displays a molecular ion peak at 103 and infrared signals at 2250 and 1600 cm^-1?

Accepted Answer

The answer of Which of the following structures is consistent...

Question 15

Which of the following statements is (are) true about a compound that has molecular ion peaks in its mass spectrum at mass 170 and 172, and shows prominent peaks in its IR spectrum at 3150-3000 and 1600 cm^-1?

Accepted Answer

The answer of Which of the following statements is (are)...

Question 16

¹³C NMR is a technique in which the total number of signals represents the number of unique carbon atoms in a molecule. Propose a structure that is consistent with the following data. (a) The IR includes peaks at 1603 and 1495 cm^-1. (b) The ¹³C NMR has a total of 7 signals. (c) The compound has one acidic proton.

Accepted Answer

The answer of ¹³C NMR is a technique in which...

Question 17

Which of the following structures is consistent with a compound that displays a molecular ion peak at 56 and infrared signals at 2250 and 3600-3200 cm^-1?

Accepted Answer

The answer of Which of the following structures is consistent...

Question 18

Which of the following structures is consistent with a compound that displays a molecular ion peak at 84 and infrared signals at 3000-2850 cm^-1 and no signals between 3000-3300 cm^-1?

Accepted Answer

The answer of Which of the following structures is consistent...

Question 19

What type of signal(s) would you observe in the mass and (or) infrared spectrum of the following compound?

Accepted Answer

The answer of What type of signal(s) would you observe...

Question 20

Examine the IR below and classify the compound.

Accepted Answer

The IR shows a broad peak at around 3300 cm-1, which indicates the presence of an –OH group, which is characteristic of alcohols. The absence of any strong absorption peaks at around 1700 cm-1 indicates that there are no carbonyl groups present, ruling out carboxylic acids. The absence of C-H stretches at around 3000 cm-1 indicates that there are no alkanes or alkenes present.

Quiz 13: Mass Spectrometry and Infrared Spectroscopy

Examine the IR below and classify the compound.

Which of the following statement(s) is (are) true about a compound that has a molecular ion peak in its mass spectrum at mass 69, and shows a prominent peak in its IR spectrum at 2250 cm-1?

Examine the IR below and classify the compound.

What type of signal(s) would you observe in the mass and (or) infrared spectrum of the following compound?

Examine the IR below and classify the compound.

When the phenol shown below is treated with KOH, it forms a product whose IR spectrum does not show an absorption in the 3200-3600 cm-1 region. Propose a structure for the product.

In a typical mass spectrum, a smaller signal is observed at a mass 1 amu higher than the molecular ion peak. Why?

Which of the following information is primarily obtained from an IR spectrum?

An IR spectrum has the following potentially important absorptions: 3091, 3067, 2963, 2921, 2252, 1603, 1499, 1455, 1416, 1078, 1031, 941, 735, and 696 cm-1. Indicate which structure corresponds to the IR data.

Which of the following compounds will have the lowest wavenumber for carbonyl absorption?

Examine the IR below and classify the compound.

What type of signal(s) would you observe in the mass and/or infrared spectrum of the following compound?

Which of the following structures is consistent with a compound that displays a molecular ion peak at 103 and infrared signals at 2250 and 1600 cm-1?

Which of the following statements is (are) true about a compound that has molecular ion peaks in its mass spectrum at mass 170 and 172, and shows prominent peaks in its IR spectrum at 3150-3000 and 1600 cm-1?

Which of the following structures is consistent with a compound that displays a molecular ion peak at 56 and infrared signals at 2250 and 3600-3200 cm-1?

Which of the following structures is consistent with a compound that displays a molecular ion peak at 84 and infrared signals at 3000-2850 cm-1 and no signals between 3000-3300 cm-1?

What type of signal(s) would you observe in the mass and (or) infrared spectrum of the following compound?

Examine the IR below and classify the compound.

Which of the following statement(s) is (are) true about a compound that has a molecular ion peak in its mass spectrum at mass 69, and shows a prominent peak in its IR spectrum at 2250 cm^-1?

When the phenol shown below is treated with KOH, it forms a product whose IR spectrum does not show an absorption in the 3200-3600 cm^-1 region. Propose a structure for the product.

An IR spectrum has the following potentially important absorptions: 3091, 3067, 2963, 2921, 2252, 1603, 1499, 1455, 1416, 1078, 1031, 941, 735, and 696 cm^-¹. Indicate which structure corresponds to the IR data.

Which of the following structures is consistent with a compound that displays a molecular ion peak at 103 and infrared signals at 2250 and 1600 cm^-1?

Which of the following statements is (are) true about a compound that has molecular ion peaks in its mass spectrum at mass 170 and 172, and shows prominent peaks in its IR spectrum at 3150-3000 and 1600 cm^-1?

Which of the following structures is consistent with a compound that displays a molecular ion peak at 56 and infrared signals at 2250 and 3600-3200 cm^-1?

Which of the following structures is consistent with a compound that displays a molecular ion peak at 84 and infrared signals at 3000-2850 cm^-1 and no signals between 3000-3300 cm^-1?