Test: Spectroscopy Level - 3 - Chemistry MCQ

The correct order of ¹H NMR chemical shift values for the labeled methyl groups in the following compound is:

The ¹H NMR spectrum of a compound with molecular formula C₃H₇NO shows the following features:

Which of the following is in agreement with this information:

The two fine–structure components of a nuclear magnet ic resonance transit ion are observed at chemical shifts of 2.142 and 2.208 ppm in a 300 MHz NMR spectrometer. Calculate the coupling constant:

 A C₅H₁₂O₂ compound has strong infrared absorption at 3300 to 3400 cm^-1 The ¹H NMR spectrum has three singlets at δ 0.9 , δ 3.45 and δ3.2 ppm; relative areas 3:2:1. The ¹³C NMR spectrum shows three signals all at higher field than δ100 ppm. Suggest a structure for this compound.

The ¹H NMR spectrum of a compound A shows a doublet and a septet. Which one of the following statements is true:

A compound of formula C₅H₁₂ gives one signal in the ¹H NMR and two signals in the ¹³C NMR spectra. The compound is:

The most appropriate spectroscopy for the identification of a nitrile group is:

Compound I gives a strong infrared absorption at 1730 cm^-1. ¹H NMR spectrum indicates that it has two types of hydrogen atoms; one H atom appearing as signlet at = 9.7 ppm and 9H atoms appearing as a singlet at = 1.2 ppm. The structure of I is:

The functionality that shows a typical characteristic peak at 2250 cm^-1 in IR is:

Consider a ¹H NMR spectrum in which a quartet and a doublet appeared at 9.72 and 2.40 ppm, respectively. Which of the following compounds is the most probable one:

The order of decreasing chemicals shift in ¹H NMR for the underlined hydrogens is:

(I) H₃C – CH₂ – CH₃
(II) H₃C – O – CH₂ – CH₃
(III) Cl₂ – CH – O – CH₂ – CH₃
(IV) Cl – CH₂ – O – CH₂ – CH₃

The number of normal modes of vibration in the benzene molecule is:

An organic compound (MF: C₈H₁₀O) exhibited the following ¹H NMR spectral data: 2.5 (3 H,s), 3.8 (3H, s), 6.8 (2 H, d, J 8 Hz), 7.2 (2 H, d, J 8 Hz) ppm. The compound among the choices is:

The ¹H NMR spectrum of 1, 4-dimethoxybenzene will have:

Appropriate ¹H NMR chemical shifts  for the protons A-D for the following compound are:

Compound A and B exhibit two singlets, each in their ¹H NMR spectra. The expected chemical shifts are at :

In the ¹H NMR spectrum recorded at 293 K, an organic compound (C₃H₇NO), exhibited signals at δ 7.8 (1H, s), 2.8 (3H, s) and 2.6 (3H, s). The compound is:

An organic compound exhibited the following ¹H NMR spectra data:

7.80 (2 H, d, J = 8 Hz), 6.80 (2 H, d, J = 8 Hz), 4.10 (2 H, q, J = 7.2 Hz), 2.4 (3H, s), 1.25 (3 H, t, J = 7.2 Hz)

The compound, among the choices given below is,

In NMR spectroscopy the product the nuclear ‘g’ factor (g_N), the nuclear magneton (β_N) and the magnetic field strength (B₀) gives the: 

Among the isomers of C₄H₆ given below, the compound which exhibits an absorption band at 3300 cm^-1 in the IR spectrum, is:

Which of the following absorptions is shown by 1, 3-butadiene in its UV absorption spectrum recorded in n-hexane (ε_max is the molar absorptivity):

Match the observed principal absorptions in the visible spectrum shown in List-I wit h the bond shows this absorption in List–II:

The correct structure of the compound based on the following characteristic spectral data is IR: 1736 cm^–1

¹H NMR: 3.59 (s, 3H), 3.32 (t, 2H), 2.25 (t, 2H), 1.85-1.75 (m, 2H), 1.73-1.62 (m, 2H)
¹³C NMR: 174.0, 51.0M 32.9, 32.8, 31.0, 23.0

In atomic absorption spectroscopy, the atomization process utilizes:

The absorption at λ_max 279 nm in the UV spectrum of acetone is due to:

An organic compound having the molecular formula C₁₀H₁₄ exhibited two singlets in the ¹H NMR spectrum and three signals in the ¹³C NMR spectrum. The compound is:

A compound with molecular formula C₅H₁₀O, exhibit following ¹H NMR spectral data - 0.95 (6H, d), 2.10 (3H, S), 2.43 (1H, m). The structure is: