Free Spectroscopy and Analysis MCQs with Answers
47 Spectroscopy and Analysis MCQs from Chemistry, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Spectroscopy studies how substances absorb, emit or interact with electromagnetic radiation. Coverage includes ultraviolet-visible absorption, infrared identification of functional groups, Beer-Lambert law, spectral interpretation and the use of spectroscopic data to identify or determine the concentration of chemical substances.
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- A. Size
- B. Position
- C. Shape
- D. Structure
Explanation: The breakdown or fragmentation of molecular ions from natural products, typically obtained by techniques such as mass spectrometry, can…
Correct answer: Structure- A. Cl− ions
- B. SO4−2 ions
- C. PO4−3 ions
- D. Cr+3 ions
Explanation: Explanation:The chromyl chloride test is performed to detect chloride ions in the qualitative analysis.
Correct answer: Cl− ions- A. Mass Spectrometry
- B. X-rays
- C. Chromatography
- D. Solvent Extraction
Explanation: A is correct as mass spectrometry is a method to differentiate between different isotopes of an element.B is incorrect as X-ray cant be…
Correct answer: Mass Spectrometry- A. R spectroscopy
- B. U.V spectroscopy
- C. Mass Spectrometry
- D. N.M.R
Explanation: Mass Spectrometry (MS) is an analytical technique used to measure the mass-to-charge ratio of ions.
Correct answer: Mass Spectrometry- A. Ethylenediamine
- B. potassium ferrocyanide
- C. dimethylglyoxime
- D. potassium permanganate
Explanation: When identifying Ni+2 ions, dimethylglyoxime is the reagent of choice. Adding dimethyl glyoxime to a solution of Ni+2 ions along with…
Correct answer: dimethylglyoxime- A. Hydroquinone
- B. Sodium thiosulphate
- C. Pyfogallal
- D. AgBr
Explanation: Sodium thiosulfate (sodium hyposulfite), Na2S2O3, is used by photographers to fix developed negatives and prints; it acts by dissolving…
Correct answer: Sodium thiosulphate- A. excited atoms
- B. Excited molecules
- C. Ground state molecules
- D. Ground state atoms
Explanation: Excited atoms: When atoms are excited, either by heating or by other means such as electrical discharge, they absorb energy and transition…
Correct answer: excited atoms- A. Mass spectrometer
- B. Cyclotron
- C. Betatron
- D. Reactor
Explanation: The mass spectrometer is a device commonly used for the detection and analysis of isotopes.
Correct answer: Mass spectrometer- A. Mass spectroscope
- B. Atomic spectroscope
- C. Spectrophotographic analyzer
- D. Spectrophotometer
Explanation: A mass spectroscope is an instrument used to determine the weight (mass) of a proton as well as positive ions.
Correct answer: Mass spectroscope- A. Sulphate radical
- B. Chloride radical
- C. Nitrate radical
- D. None of the above
Explanation: The brown ring test is a qualitative analysis technique used to detect the presence of nitrate ions.
Correct answer: Nitrate radical- A. Imethylglyoxime
- B. Tollen's reagent
- C. Nessler's reagent
- D. Magneson reagen
Explanation: Nessler's reagent can be used to detect the presence of NH4+ ions in water as brown ppt is formed. Therefore the correct answer will be C.
Correct answer: Nessler's reagent- A. Microwave
- B. Infrared
- C. Visible
- D. X-rays
Explanation: The difference in energy between two vibrational states is equal to the energy associated with the wavelength of radiation that was…
Correct answer: Infrared- A. Molecule may gain an electron to form a molecular anion.
- B. Molecule may lose an electron to form a molecular cation.
- C. Molecular cations are less abundant than molecular anions.
- D. These molecular ions can be formed by passing a high-energy electron beam through a gas.
Explanation: Abundance of cationic molecular ions is due to the ability to stabilize unpaired electrons which makes the formation of cationic molecular…
Correct answer: Molecular cations are less abundant than molecular anions.- A. The most direct and accurate method for determining atomic masses uses mass spectrometry.
- B. An indirect but precise method for determining molecular masses is through mass spectrometry.
- C. Collision between electrons and atoms produces negative ions by the absorption of electrons by atoms or molecules.
- D. The first significant application of mass spectrometry was demonstrating the detection of isotopes of Argon.
Explanation: Electron Collision. Often, electron collisions with gas molecules result in electron attachment to the molecule, which forms a negative ion.
Correct answer: Collision between electrons and atoms produces negative ions by the absorption of electrons by atoms or molecules.- A. Solute
- B. Solvent
- C. Concentration
- D. All of the above
Explanation: Under defined conditions of solvent, pH, and temperature the molar absorption coefficient for a particular compound is a constant at the…
Correct answer: All of the above- A. Accurate but more time consuming
- B. Accurate, rapid but chemicals are used in large amounts
- C. Accurate, rapid but sophisticated and complicated
- D. Accurate, simple and less time consuming
Explanation: The modern methods used by scientists to identify and differentiate between cell structures are efficient, accurate, simple, and less…
Correct answer: Accurate, simple and less time consuming- A. Microwave
- B. Radio wave
- C. Infrared region
- D. X-rays
Explanation: NMR spectroscopy works by applying a radio frequency to the sample, specific to the nuclei of interest.
Correct answer: Radio wave- A. σ - σ
- B. d - d
- C. π - π
- D. π - σ
Explanation: d-d transitions are electronic transitions that occur between the molecular orbitals that are mostly metallic in character; specifically…
Correct answer: d - d- A. No absorption
- B. 50% absorption
- C. 75% absorption
- D. 100% absorption
Explanation: When IR radiation is passed through a sample, some of it is absorbed and some of it paasses through (transmitted).
Correct answer: No absorption- A. δ = 10 - t
- B. δ = 10 + t
- C. t = δ - 10
- D. t = 10 - δ
Explanation: In NMR spectroscopy, δ (delta) represents the chemical shift, while t is another scale used to express the same concept.
Correct answer: δ = 10 - t