Free Analytical Chemistry MCQs with Answers
105 Analytical Chemistry MCQs from Chemistry, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Analytical chemistry identifies and measures substances using separation and instrumental methods. Chromatography is studied through stationary and mobile phases, retention and Rf values, while spectroscopy connects absorption of electromagnetic radiation with molecular structure and supports qualitative and quantitative analysis through techniques such as UV-visible and infrared spectroscopy.
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Read the Analytical Chemistry notesFree MDCAT chapter notes with key terms105 questions · page 5 of 6
- A. Alcohol
- B. Adeline
- C. Piece of paper
- D. Water absorbed on paper
Explanation: Water absorbed on paper: This option is correct. In paper chromatography, the stationary phase is usually achieved by impregnating the…
Correct answer: Water absorbed on paper- A. Paper chromatography is an example of partition chromatography.
- B. Paper chromatography is most commonly used to separate biologically active substances.
- C. Paper chromatography can also be applied for separating some inorganic ions.
- D. Paper chromatography is always used for quantitative analysis.
Explanation: There are limitations to paper chromatography that include;Large quantities of sample cannot be applied on paper chromatography.In…
Correct answer: Paper chromatography is always used for quantitative analysis.- 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- A. Mg (NO3)2
- B. Mg (ClO4)2
- C. Mg (OH)2
- D. Mg (ClO2)2
Explanation: The correct answer is Mg (ClO4)2, or magnesium perchlorate, which is widely used in combustion analysis as a drying agent due to its…
Correct answer: Mg (ClO4)2- A. Different energies
- B. Equal energies
- C. Zero energies
- D. High energies
Explanation: In the absence of an applied magnetic field, the spin states of a nucleus of an atom have equal energies.
Correct answer: Equal energies