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 4 of 6
- A. 24.32 amu
- B. 25.32 amu
- C. 26.32 amu
- D. 27.32 amu
Explanation: To calculate the average atomic mass, we use the formula:Average atomic mass=(Abundance1×Atomic mass1)+(Abundance2×Atomic…
Correct answer: 24.32 amu- A. n → Π
- B. Π → Π
- C. 8 → 8
- D. n → 8
Explanation: This transition involves the excitation of an electron from a non-bonding orbital (n) to another orbital (8).
Correct answer: n → 8- A. Number of isotopes
- B. Mass number
- C. Relative abundace of isotopes
- D. Number of protons
Explanation: Option c is the correct answer. The height of a peak in a mass spectrum is directly proportional to the relative abundance of ions with…
Correct answer: Relative abundace of isotopes- A. Ultraviolet
- B. Infrared
- C. Radio waves
- D. Microwaves
Explanation: Infrared radiation is involved in bond vibrations. When molecules vibrate, their bonds stretch, bend, and twist.
Correct answer: Infrared- A. 3200cm-1
- B. 1200cm-1
- C. 800cm-1
- D. 1720cm-1
Explanation: This is the correct answer. The characteristic signal of the carbonyl carbon in acetone (CH3COCH3) is typically found in the region around…
Correct answer: 1720cm-1- A. Around 10-7 torr
- B. 1 torr
- C. Around 10-3 torr
- D. 10-7 torr
Explanation: Explanation:The pressure of these vapors is kept very low that 10-6 to 10-7 torr.
Correct answer: Around 10-7 torr- A. Electrons
- B. Protons
- C. Alpha particles
- D. Neutrons
Explanation: α-particles consist of 2 protons and 2 neutrons, which have 4 times higher mass than neutrons, and thus low penetration power.
Correct answer: Neutrons- A. W. Roentgen
- B. De Broglie
- C. Young
- D. Michelson
Explanation: The correct answer is A. Wilhelm Conrad Roentgen discovered X-rays on November 8, 1895, while experimenting with cathode-ray tubes.
Correct answer: W. Roentgen- A. 35.5
- B. 37
- C. 4.3
- D. 78
Explanation: c) 4.3:The m/e value of 4.3 is an unusual and specific value. It is not commonly associated with any ions or fragments that would be…
Correct answer: 4.3- A. Propane
- B. Butane
- C. 2-methylpropane
- D. 2,2 - dimethylpropane
Explanation: b) Butane:Butane is a four-carbon alkane with the molecular formula C4H10.
Correct answer: Butane- A. C2H4
- B. C5H11N
- C. C7H13O
- D. C2H5F
Explanation: b) C5H11N:The molecular ion occurs at m/e 86. The empirical formula C5H11N corresponds to the compound pentylamine, which has a molecular…
Correct answer: C5H11N- A. CuCl2
- B. ZnCl2
- C. HgCl2
- D. C4H9NH4+Cl-
Explanation: d) C4H9NH4+Cl- (Tetra-n-butylammonium chloride):Tetra-n-butylammonium chloride is a quaternary ammonium salt and does not contain a metal…
Correct answer: C4H9NH4+Cl-- A. Texture of surface
- B. Hardness
- C. Passing X-rays
- D. Placing in magnetic field
Explanation: The explanation for this question will be added soon.
Correct answer: Passing X-rays- 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. A non-polar organic solvent
- B. Water
- C. Sulfuric acid
- D. Silver nitrate
Explanation: The correct answer is a non-polar organic liquid. In paper chromatography, the mobile phase is typically a non-polar organic solvent that…
Correct answer: A non-polar organic solvent- A. Elemental Analysis
- B. Qualitative Analysis
- C. Industrial Purification
- D. Structural Analysis
Explanation: Explanation:Chromatography is very useful for organic synthesis for separation, purification, and isolation of products.
Correct answer: Qualitative Analysis- A. Sublimation
- B. Filtration
- C. Chromatography
- D. Solvent extraction
Explanation: A is incorrect as sublimation purifies solids rather than identify themB is incorrect as filtration separates insoluble solutes from…
Correct answer: Chromatography- 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