TRB PG Assistant – Chemistry 75 MCQS QUIZ

TRB PG Assistant – Chemistry – English Medium

Set 14 | 5 MCQ Tests × 15 Questions = 75 Questions

Submit each test to display the correct answer under every question.

Test 1 – 15 Questions

1. Elements with a negative electron gain enthalpy tend to:

A) Lose electrons easilyB) Gain electrons easilyC) Form positive ionsD) Be noble gases

Correct Answer: B) Gain electrons easily

Study & practice: Ravi Test Papers

2. Atomic radius generally decreases across a period due to:

A) Increase in nuclear charge and shielding effectB) Decrease in nuclear charge and shielding effectC) Increase in nuclear charge and constant shielding effectD) Decrease in nuclear charge and increase in shielding effect

Correct Answer: C) Increase in nuclear charge and constant shielding effect

Study & practice: Ravi Test Papers

3. Which type of radiation has the greatest penetrating power and requires thick shielding like lead or concrete?

A) Alpha particlesB) Beta particlesC) Gamma raysD) Neutrons

Correct Answer: C) Gamma rays

Study & practice: TNPSC 700+ Files

4. Which of the following is an example of a soft acid?

A) Li+B) Mg2+C) Ca2+D) Hg2+

Correct Answer: D) Hg2+

Study & practice: TNPSC Practice

5. What is the unit of wavelength for electrons used in electron microscopy, which contributes to their high resolution?

A) Nanometers (nm)B) Picometers (pm)C) Angstroms (Å)D) Micrometers (µm)

Correct Answer: B) Picometers (pm)

Study & practice: TNPSC Tamil 300+ Files

6. What is the fundamental basis for the signal detected in ESR spectroscopy?

A) Absorption of energy when the microwave photon energy matches the spin state splitting.B) Emission of energy as the electron relaxes from a higher orbital.C) Scattering of microwave radiation by the sample.D) Change in the sample's electrical conductivity.

Correct Answer: A) Absorption of energy when the microwave photon energy matches the spin state splitting.

Study & practice: MCQs 600+ Quizzes

7. The molar absorptivity (ε) is a measure of:

A) The concentration of the absorbing species.B) The path length of the light through the sample.C) How strongly a chemical species absorbs light at a particular wavelength.D) The total amount of light absorbed by the sample.

Correct Answer: C) How strongly a chemical species absorbs light at a particular wavelength.

Study & practice: 11th Standard Practice

8. The disconnection of a C-N bond in an amide (R-CO-NR'R'') typically leads to synthons related to:

A) A carboxylic acid and an amine.B) An acyl cation and an amine.C) A carbanion and an imine.D) An aldehyde and ammonia.

Correct Answer: A) A carboxylic acid and an amine.

Study & practice: 12th Standard Practice

9. What is the purpose of the parameter λ in the perturbation theory Hamiltonian H = H0 + λV?

A) It represents the energy of the system.B) It is a mathematical parameter that smoothly turns on the perturbation, allowing for series expansion.C) It is the quantum number of the state.D) It is the charge of the electron.

Correct Answer: B) It is a mathematical parameter that smoothly turns on the perturbation, allowing for series expansion.

Study & practice: JEE Maths

10. What is the primary driving force for the stability of aromatic compounds?

A) Sigma bond strengthB) Pi bond strengthC) Delocalization of pi electronsD) Steric strain relief

Correct Answer: C) Delocalization of pi electrons

Study & practice: JEE Physics

11. Which of the following is a common application of turbidimetry?

A) Measuring the concentration of dissolved ions.B) Determining the purity of solvents.C) Assessing the clarity of drinking water.D) Analyzing the composition of gases.

Correct Answer: C) Assessing the clarity of drinking water.

Study & practice: JEE Chemistry

12. In the absence of other relaxation mechanisms, T2 is always:

A) Shorter than T1B) Longer than T1C) Equal to T1D) Zero

Correct Answer: A) Shorter than T1

Study & practice: Ravi Test Papers

13. In the eigenvalue equation Âψ = aψ, what does 'a' represent?

A) The operatorB) The eigenfunctionC) The eigenvalueD) The wavefunction

Correct Answer: C) The eigenvalue

Study & practice: Ravi Test Papers

14. Which technique would be most appropriate to study the dehydration of a hydrated salt?

A) DSCB) DTAC) TGAD) Atomic Absorption Spectroscopy

Correct Answer: C) TGA

Study & practice: TNPSC 700+ Files

15. Which statement best describes the bonding in NO according to MOT?

A) It is diamagnetic with a bond order of 2.B) It is paramagnetic with a bond order of 2.5.C) It is diamagnetic with a bond order of 2.5.D) It is paramagnetic with a bond order of 2.

Correct Answer: B) It is paramagnetic with a bond order of 2.5.

Study & practice: TNPSC Practice

Test 2 – 15 Questions

1. Which of the following is a common method for the synthesis of pyrazines, a six-membered heterocycle with two nitrogen atoms at positions 1 and 4?

A) Staedel-Rugheimer pyrazine synthesisB) Hantzsch pyridine synthesisC) Paal-Knorr synthesisD) Fischer indole synthesis

Correct Answer: A) Staedel-Rugheimer pyrazine synthesis

Study & practice: TNPSC Tamil 300+ Files

2. What fundamental property of electrons does Electron Spin Resonance (ESR) spectroscopy directly probe?

A) Their chargeB) Their massC) Their spin angular momentumD) Their orbital angular momentum

Correct Answer: C) Their spin angular momentum

Study & practice: MCQs 600+ Quizzes

3. Which of the following applications is well-suited for ESR spectroscopy?

A) Determining the exact molecular weight of large polymersB) Studying reaction mechanisms involving free radicalsC) Measuring the bond lengths of stable moleculesD) Analyzing the composition of alloys

Correct Answer: B) Studying reaction mechanisms involving free radicals

Study & practice: 11th Standard Practice

4. Why does a cation have a smaller ionic radius than its parent atom?

A) Increased number of electronsB) Decreased effective nuclear charge per electron and reduced electron-electron repulsionC) Increased shielding effectD) Addition of neutrons

Correct Answer: B) Decreased effective nuclear charge per electron and reduced electron-electron repulsion

Study & practice: 12th Standard Practice

5. The sol-gel method is a wet chemical synthesis technique that typically starts with:

A) Metal oxides in solid formB) Gaseous precursorsC) Molecular precursors in solution (e.g., alkoxides)D) Plasma

Correct Answer: C) Molecular precursors in solution (e.g., alkoxides)

Study & practice: JEE Maths

6. What is the function of the protein ICP (Iron-Regulated Transporter 1)?

A) Iron exportB) Iron import into cellsC) Copper transportD) Zinc storage

Correct Answer: B) Iron import into cells

Study & practice: JEE Physics

7. The observation that (+) lactic acid is dextrorotatory and (-) lactic acid is levorotatory indicates that:

A) They are identical compoundsB) They are enantiomersC) They are diastereomersD) One is achiral

Correct Answer: B) They are enantiomers

Study & practice: JEE Chemistry

8. What is the primary assumption of the F-test used in ANOVA?

A) The data are independent and normally distributed, and the variances of the groups are equal (homoscedasticity).B) The data are paired.C) The sample sizes are unequal.D) The population standard deviations are known.

Correct Answer: A) The data are independent and normally distributed, and the variances of the groups are equal (homoscedasticity).

Study & practice: Ravi Test Papers

9. What is meant by 'relaxation' in the context of magnetic resonance?

A) The process of returning to thermal equilibrium after perturbationB) The absorption of energy from the electromagnetic fieldC) The splitting of spectral linesD) The decrease in magnetic field strength

Correct Answer: A) The process of returning to thermal equilibrium after perturbation

Study & practice: Ravi Test Papers

10. Optical Rotatory Dispersion (ORD) is a more detailed analysis than simple polarimetry because it:

A) Measures the intensity of light directlyB) Analyzes the rotation at multiple wavelengthsC) Only works for achiral compoundsD) Provides information about the molecular weight

Correct Answer: B) Analyzes the rotation at multiple wavelengths

Study & practice: TNPSC 700+ Files

11. The different spatial arrangements of a molecule that arise due to rotation about single bonds are called:

A) Configurational isomersB) Conformational isomersC) Geometric isomersD) Stereoisomers

Correct Answer: B) Conformational isomers

Study & practice: TNPSC Practice

12. What type of information is primarily obtained from AES?

A) Elemental compositionB) Isotopic compositionC) Molecular structureD) Bulk crystalline structure

Correct Answer: A) Elemental composition

Study & practice: TNPSC Tamil 300+ Files

13. The 'Great Pacific Garbage Patch' is a prominent example of:

A) Ocean acidificationB) Marine plastic pollutionC) Oil spillsD) Thermal pollution

Correct Answer: B) Marine plastic pollution

Study & practice: MCQs 600+ Quizzes

14. If measurements of a substance are 2.55 g, 2.57 g, and 2.56 g, and the true value is 3.00 g, what is indicated?

A) High accuracy and high precisionB) Low accuracy and low precisionC) Low accuracy and high precisionD) High accuracy and low precision

Correct Answer: C) Low accuracy and high precision

Study & practice: 11th Standard Practice

15. Which of the following is NOT a type of molecular orbital formed from the combination of atomic orbitals?

A) Bonding molecular orbitalB) Antibonding molecular orbitalC) Non-bonding molecular orbitalD) Hybrid molecular orbital

Correct Answer: D) Hybrid molecular orbital

Study & practice: 12th Standard Practice

Test 3 – 15 Questions

1. Which of the following is a common application of degenerate perturbation theory?

A) Calculating the ground state energy of Helium.B) Describing the Zeeman effect (atom in a magnetic field).C) Finding the energy levels of a harmonic oscillator.D) Solving the hydrogen atom exactly.

Correct Answer: B) Describing the Zeeman effect (atom in a magnetic field).

Study & practice: JEE Maths

2. Water is an example of which type of non-aqueous solvent?

A) ProtogenicB) ProtophilicC) AproticD) Amphiprotic

Correct Answer: D) Amphiprotic

Study & practice: JEE Physics

3. What is the significance of the first column in a character table?

A) Symmetry operationsB) Classes of symmetry operationsC) Irreducible representationsD) Characters of the identity operation

Correct Answer: C) Irreducible representations

Study & practice: JEE Chemistry

4. Which microscopy technique provides the highest resolution currently available?

A) Optical MicroscopyB) Scanning Electron Microscopy (SEM)C) Transmission Electron Microscopy (TEM)D) Scanning Tunneling Microscopy (STM)

Correct Answer: D) Scanning Tunneling Microscopy (STM)

Study & practice: Ravi Test Papers

5. What is the primary purpose of using significant figures in scientific calculations?

A) To make numbers look neater.B) To indicate the precision of the measurements used.C) To increase the accuracy of the results.D) To ensure all numbers have the same number of digits.

Correct Answer: B) To indicate the precision of the measurements used.

Study & practice: Ravi Test Papers

6. Which of the following is a purine base found in nucleic acids?

A) CytosineB) ThymineC) UracilD) Guanine

Correct Answer: D) Guanine

Study & practice: TNPSC 700+ Files

7. Which of the following has a trigonal planar molecular geometry?

A) NH3B) H2OC) CH4D) BF3

Correct Answer: D) BF3

Study & practice: TNPSC Practice

8. What does the integration of an ESR spectrum signal intensity correspond to?

A) The concentration of paramagnetic speciesB) The relaxation timeC) The g-factor valueD) The hyperfine splitting constant

Correct Answer: A) The concentration of paramagnetic species

Study & practice: TNPSC Tamil 300+ Files

9. Which phenomenon in XPS results in satellite peaks alongside the main photoelectron peak due to simultaneous electronic transitions?

A) Shake-up and shake-off processesB) Spin-orbit splittingC) Plasmon lossD) Auger decay

Correct Answer: A) Shake-up and shake-off processes

Study & practice: MCQs 600+ Quizzes

10. What is the main objective of 'sub-sampling'?

A) To collect the entire batchB) To reduce the bulk sample to a manageable size for analysisC) To increase the concentration of the analyteD) To homogenize the original material

Correct Answer: B) To reduce the bulk sample to a manageable size for analysis

Study & practice: 11th Standard Practice

11. The probability of a neutron-induced reaction is often described by its:

A) Half-lifeB) Decay constantC) Cross sectionD) Q-value

Correct Answer: C) Cross section

Study & practice: 12th Standard Practice

12. The stability of carbanions decreases with the introduction of:

A) Electron-donating groupsB) Electron-withdrawing groupsC) Alkyl groupsD) Aromatic groups

Correct Answer: A) Electron-donating groups

Study & practice: JEE Maths

13. What is the term for a nuclear reaction where the incident particle transfers energy and momentum to the target nucleus, but does not form a compound nucleus?

A) Compound nucleus reactionB) Direct reactionC) Fusion reactionD) Fission reaction

Correct Answer: B) Direct reaction

Study & practice: JEE Physics

14. For a molecule with D3h symmetry (like BF3), which vibrational modes are IR active and Raman inactive?

A) A1' and E' modesB) A2'' and E' modesC) A1' and A2'' modesD) Only E' modes

Correct Answer: B) A2'' and E' modes

Study & practice: JEE Chemistry

15. The cluster formula [Os10(CO)32]2- has a skeletal electron count that suggests a structure related to:

A) A single metal atomB) A diatomic metal unitC) A closed polyhedral cageD) A linear chain

Correct Answer: C) A closed polyhedral cage

Study & practice: Ravi Test Papers

Test 4 – 15 Questions

1. What does 'depth profiling' aim to achieve in solid surface analysis?

A) To understand the composition variation from the surface into the bulkB) To measure the surface areaC) To determine the crystal structureD) To identify subsurface defects

Correct Answer: A) To understand the composition variation from the surface into the bulk

Study & practice: Ravi Test Papers

2. Which of the following is a characteristic feature of pericyclic reactions?

A) Radical intermediatesB) Concerted mechanismC) Stepwise mechanismD) Ionic intermediates

Correct Answer: B) Concerted mechanism

Study & practice: TNPSC 700+ Files

3. Cyclohexane exists predominantly in which conformation?

A) BoatB) Twist-boatC) Half-chairD) Chair

Correct Answer: D) Chair

Study & practice: TNPSC Practice

4. What is the symmetry of the z-axis rotation (Rz) in the C2v point group?

A) A1B) B1C) B2D) A2

Correct Answer: D) A2

Study & practice: TNPSC Tamil 300+ Files

5. Which of the following is a characteristic feature of the SN2 transition state?

A) A planar carbocation.B) A trigonal bipyramidal arrangement around the central carbon.C) A tetrahedral intermediate.D) A linear arrangement of atoms.

Correct Answer: B) A trigonal bipyramidal arrangement around the central carbon.

Study & practice: MCQs 600+ Quizzes

6. Which mathematical entity is used to represent physical observables in quantum mechanics?

A) ScalarB) VectorC) OperatorD) Tensor

Correct Answer: C) Operator

Study & practice: 11th Standard Practice

7. The stability order of free radicals is generally similar to that of:

A) CarbocationsB) CarbanionsC) CarbenesD) Nitrenes

Correct Answer: A) Carbocations

Study & practice: 12th Standard Practice

8. The non-zero commutator [x̂, p̂ₓ] = iħ implies that position and momentum are:

A) Compatible observablesB) Incompatible observablesC) Commuting observablesD) Identical observables

Correct Answer: B) Incompatible observables

Study & practice: JEE Maths

9. What is the IUPAC name for CH3-CH=CH-CH3?

A) But-1-eneB) But-2-eneC) ButeneD) 1,2-Butene

Correct Answer: B) But-2-ene

Study & practice: JEE Physics

10. Which of the following is a consequence of the anti-periplanar requirement in E2 reactions?

A) Syn elimination is favored.B) The leaving group and beta-hydrogen must be on the same side of the C-C bond.C) The leaving group and beta-hydrogen must be on opposite sides of the C-C bond.D) E2 reactions are generally slow.

Correct Answer: C) The leaving group and beta-hydrogen must be on opposite sides of the C-C bond.

Study & practice: JEE Chemistry

11. Bioaccumulation refers to:

A) The rapid breakdown of pollutants in the environmentB) The accumulation of pollutants in organisms over timeC) The dispersal of pollutants over a large areaD) The conversion of waste into usable energy

Correct Answer: B) The accumulation of pollutants in organisms over time

Study & practice: Ravi Test Papers

12. Which statement best describes the sensitivity of ESR compared to NMR?

A) ESR is generally less sensitive than NMRB) ESR is generally more sensitive than NMR for the same concentrationC) Both techniques have similar sensitivityD) Sensitivity depends only on the magnetic field strength

Correct Answer: B) ESR is generally more sensitive than NMR for the same concentration

Study & practice: Ravi Test Papers

13. The molecular geometry of CO2 is linear. This is consistent with the VSEPR model because the central carbon atom has two electron domains (two double bonds), which arrange themselves linearly.

A) True, linear arrangement minimizes repulsion for two electron domains.B) False, CO2 is a polar molecule and has a bent shape.C) True, but only if the bonds are single bonds.D) False, double bonds exert different repulsions than single bonds in VSEPR.

Correct Answer: A) True, linear arrangement minimizes repulsion for two electron domains.

Study & practice: TNPSC 700+ Files

14. Which of the following is a characteristic of the Bohr effect in hemoglobin?

A) Increased oxygen affinity at high pHB) Decreased oxygen affinity at low pHC) Increased oxygen affinity at high CO2 concentrationD) Decreased oxygen affinity at low CO2 concentration

Correct Answer: B) Decreased oxygen affinity at low pH

Study & practice: TNPSC Practice

15. A broad and strong absorption band between 1300 and 1000 cm⁻¹ is characteristic of:

A) C-H bondB) C=O bondC) C-O bondD) C≡N bond

Correct Answer: C) C-O bond

Study & practice: TNPSC Tamil 300+ Files

Test 5 – 15 Questions

1. In XPS, what determines the kinetic energy of the emitted photoelectrons?

A) The binding energy of the electron and the energy of the incident X-ray photonB) The work function of the material and the photon energyC) The electron's velocity and the detector's efficiencyD) The density of states and the photon flux

Correct Answer: A) The binding energy of the electron and the energy of the incident X-ray photon

Study & practice: MCQs 600+ Quizzes

2. What is the symmetry of the vibrational modes that correspond to stretching of the C-H bonds in benzene (D6h point group)?

A) A1g + E1uB) A1g + E2gC) B1g + E2uD) A2u + E1g

Correct Answer: B) A1g + E2g

Study & practice: 11th Standard Practice

3. In 13C NMR, what is the typical chemical shift range for carbons in aromatic rings?

A) 0-50 ppmB) 50-100 ppmC) 100-150 ppmD) 150-200 ppm

Correct Answer: C) 100-150 ppm

Study & practice: 12th Standard Practice

4. Which type of molecule typically exhibits the mutual exclusion principle?

A) Molecules with no symmetry elementsB) Chiral moleculesC) Molecules with a center of inversion (centrosymmetric molecules)D) Linear molecules without a center of inversion

Correct Answer: C) Molecules with a center of inversion (centrosymmetric molecules)

Study & practice: JEE Maths

5. The characteristic absorption of aromatic C=C stretching vibrations is observed in the region:

A) 3100-3000 cm⁻¹B) 1680-1640 cm⁻¹C) 1600-1450 cm⁻¹D) 900-650 cm⁻¹

Correct Answer: C) 1600-1450 cm⁻¹

Study & practice: JEE Physics

6. The C-H stretching vibrations for sp² hybridized carbon atoms (alkenes, aromatics) are typically observed above:

A) 3100 cm⁻¹B) 3000 cm⁻¹C) 2900 cm⁻¹D) 2850 cm⁻¹

Correct Answer: B) 3000 cm⁻¹

Study & practice: JEE Chemistry

7. The 'delta-bond' in metal clusters arises from the overlap of:

A) s-orbitalsB) p-orbitalsC) d-orbitalsD) f-orbitals

Correct Answer: C) d-orbitals

Study & practice: Ravi Test Papers

8. Which of the following diatomic molecules is diamagnetic?

A) B2B) C2C) N2D) O2

Correct Answer: C) N2

Study & practice: Ravi Test Papers

9. The concept of energy quantization was a radical departure from classical physics because classical physics assumed energy to be:

A) DiscreteB) QuantizedC) ContinuousD) Atomic

Correct Answer: C) Continuous

Study & practice: TNPSC 700+ Files

10. What is the term for the process where a radioactive nucleus loses energy by emitting particles or electromagnetic waves?

A) Nuclear fissionB) Nuclear fusionC) Radioactive decayD) Spallation

Correct Answer: C) Radioactive decay

Study & practice: TNPSC Practice

11. The conversion of an alkene to an alkyl halide is an electrophilic addition reaction. What is the general reagent used?

A) HX (where X is a halogen)B) H2/PdC) O3D) KMnO4

Correct Answer: A) HX (where X is a halogen)

Study & practice: TNPSC Tamil 300+ Files

12. What is the threshold frequency?

A) The maximum frequency of light that can cause electron emission.B) The minimum frequency of light required to cause electron emission.C) The frequency of light where the work function is zero.D) The frequency of light where electrons are emitted with maximum kinetic energy.

Correct Answer: B) The minimum frequency of light required to cause electron emission.

Study & practice: MCQs 600+ Quizzes

13. The stereochemistry of hybrid orbitals refers to their:

A) Energy levelsB) Spatial orientationC) Number of electronsD) Bond polarity

Correct Answer: B) Spatial orientation

Study & practice: 11th Standard Practice

14. What is the Hückel approximation for the interaction between p orbitals on the same carbon atom (Coulomb integral)?

A) Sii = 1B) Hii = αC) Hij = βD) Sij = 0

Correct Answer: B) Hii = α

Study & practice: 12th Standard Practice

15. What happens to the heat flow signal in DSC during an exothermic process?

A) It increasesB) It decreasesC) It remains constantD) It becomes zero

Correct Answer: A) It increases

Study & practice: JEE Maths

© Ravi Test Papers | TRB PG Assistant Chemistry – Set 14 MCQ Practice