100+ Free BCS Written Chemistry Practice Questions

Prepare for the BCS Written Post-Related Chemistry, Subject Code 531, Total Marks 200 exam with instant access — no signup required.

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Key Facts: BCS Written Chemistry Exam

200 marks

Official Chemistry paper (Part I 100 + Part II 100)

BPSC written syllabus, subject code 531

4 hours

Duration used for BPSC 200-mark written papers

Longstanding BPSC sitting practice; confirm current routine

50% aggregate

Pass standard on the 900-mark written examination

BPSC BCS examination page

Tk. 200 / Tk. 50

50th BCS application fee (general / reduced categories)

50th BCS circular reporting; confirm live Teletalk circular

Subject code 531

Post-related Chemistry paper identity

BPSC written syllabus

Descriptive, not MCQ

Official item type for Chemistry 531

BPSC written examination format

BPSC Chemistry 531 is a 200-mark, 4-hour descriptive written paper (Part I 100 + Part II 100) inside the 900-mark BCS written stage (50% aggregate pass). Application fee Tk. 200 general / Tk. 50 reduced categories (50th BCS reporting); no separate written fee. This page offers 100 English MCQs as a study aid, not an official-paper simulation.

Sample BCS Written Chemistry Practice Questions

Try these sample questions to test your BCS Written Chemistry exam readiness. Each question includes a detailed explanation. Start the interactive quiz above for the full 100+ question experience with AI tutoring.

1At constant temperature, which statement is Boyle's law for a fixed amount of ideal gas?

A.Volume is directly proportional to absolute temperature

B.Pressure is directly proportional to absolute temperature

C.Volume is directly proportional to the number of moles

D.Pressure is inversely proportional to volume

Explanation: Boyle's law states that PV is constant at constant T and n, so P is inversely proportional to V. Plotting P against 1/V is linear for an ideal gas under those constraints.

2What volume is occupied by 2.00 mol of an ideal gas at 1.00 atm and 273 K? (R = 0.0821 L atm mol⁻¹ K⁻¹)

A.22.4 L

B.11.2 L

C.44.8 L

D.67.2 L

Explanation: From PV = nRT, V = nRT/P = (2.00 × 0.0821 × 273) / 1.00 = 44.8 L. One mole occupies about 22.4 L at 1 atm and 273 K, so two moles occupy twice that volume.

3By Graham's law, the ratio of effusion rates of H₂ to O₂ (M = 2.0 and 32 g mol⁻¹) is

A.2 : 1

B.4 : 1

C.8 : 1

D.16 : 1

Explanation: Graham's law gives rate ∝ 1/√M, so rate(H₂)/rate(O₂) = √(M_O₂/M_H₂) = √(32/2) = √16 = 4. Hydrogen therefore effuses four times as fast as oxygen at the same T.

4According to kinetic molecular theory, the average translational kinetic energy of an ideal-gas molecule depends only on

A.molar mass

B.pressure

C.absolute temperature

D.collision frequency

Explanation: The mean translational KE per molecule is (3/2)kT and per mole is (3/2)RT. It is independent of identity, pressure, and volume for an ideal gas.

5The rms speed of O₂ (M = 0.0320 kg mol⁻¹) at 300 K is closest to which value? (R = 8.314 J K⁻¹ mol⁻¹)

A.215 m s⁻¹

B.342 m s⁻¹

C.484 m s⁻¹

D.726 m s⁻¹

Explanation: v_rms = √(3RT/M) = √(3 × 8.314 × 300 / 0.0320) = √(233831) ≈ 484 m s⁻¹. Molar mass must be in kg mol⁻¹ so that the result is in m s⁻¹.

6A gas cannot be liquefied by pressure alone, however high, when it is

A.below its Boyle temperature

B.at its inversion temperature

C.above its critical temperature

D.at its triple-point temperature

Explanation: Above the critical temperature T_c there is no distinct liquid–gas coexistence; compression yields only a supercritical fluid. Liquefaction by pressure therefore requires T < T_c.

7In the van der Waals equation (P + a n²/V²)(V − n b) = nRT, the parameter a primarily corrects for

A.finite molecular volume

B.attractive intermolecular forces

C.quantum zero-point energy

D.gravitational attraction between molecules

Explanation: The a n²/V² term raises the observed pressure toward the ideal kinetic pressure, correcting for attractive forces that reduce momentum transfer to the wall. Parameter b corrects for excluded volume.

8For an isothermal expansion of an ideal gas, which quantity is necessarily zero?

A.q

B.w

C.ΔU

D.ΔS

Explanation: U of an ideal gas depends only on T, so ΔU = 0 for any isothermal process. Then q = −w from the first law (ΔU = q + w). Entropy of the system still increases in a reversible isothermal expansion.

9A reaction has ΔH = −90.0 kJ mol⁻¹ and ΔS = −150 J K⁻¹ mol⁻¹. What is ΔG at 300 K?

A.−45.0 kJ mol⁻¹

B.−135 kJ mol⁻¹

C.+45.0 kJ mol⁻¹

D.−90.0 kJ mol⁻¹

Explanation: Convert ΔS to −0.150 kJ K⁻¹ mol⁻¹. Then ΔG = ΔH − TΔS = −90.0 − (300)(−0.150) = −90.0 + 45.0 = −45.0 kJ mol⁻¹. The process is still spontaneous at 300 K because |ΔH| exceeds T|ΔS|.

10A process with ΔH > 0 and ΔS > 0 is spontaneous

A.at all temperatures

B.only at sufficiently high temperature

C.only at sufficiently low temperature

D.never, because enthalpy increases

Explanation: ΔG = ΔH − TΔS. When both ΔH and ΔS are positive, −TΔS becomes more negative as T rises, so ΔG < 0 only above T = ΔH/ΔS. Endothermic entropy-driven processes (for example some dissolutions) follow this pattern.

About the BCS Written Chemistry Exam

BCS Written Post-Related Chemistry (subject code 531) is a 200-mark descriptive paper for technical/professional and dual-cadre BCS applicants who nominate Chemistry. Part I and Part II carry 100 marks each and together span physical, inorganic, and organic chemistry, including chromatography and spectroscopy. The official paper is handwritten, not multiple choice. This free bank is an English-language MCQ study adaptation of the BPSC syllabus—not an official translation, format simulation, or substitute for writing practice.

Assessment

Two 100-mark parts (200 marks total). Part I covers gas laws and thermodynamics, electrochemistry, colligative properties and phase rule, equilibria and kinetics, pH and buffers, conductance and instrumental analysis, atomic structure and group chemistry, radioactivity and environmental chemistry, organic compounds and substitution, and industrial manufacture and waste. Part II covers acids/bases/nucleophiles/electrophiles, HSAB and frontier orbitals, reaction mechanism, chirality and ORD/CD, atropisomerism, UV/IR/Raman/ESR/NMR/MS, chromatography, and carbohydrates, proteins, vitamins, hormones, antibiotics, alkaloids, and dyes. Official answers are descriptive. This page is a free English MCQ study adaptation.

Time Limit

4 hours (duration used for BPSC 200-mark written papers; confirm the current examination routine)

Passing Score

50% aggregate on the 900-mark written examination (BPSC official page); per-paper minima also apply as set by BPSC

Exam Fee

Tk. 200 general (50th BCS); Tk. 50 for ethnic minority, persons with disabilities, and third-gender categories; no separate written-stage fee. Confirm the live circular. (Bangladesh Public Service Commission (BPSC))

BCS Written Chemistry Exam Content Outline

20%

Part I — Physical chemistry and instrumental analysis

Gas laws, kinetic theory, liquefaction, enthalpy and thermodynamics (ΔH, ΔS, ΔG), electrode potentials, voltaic cells, Nernst equation, colligative properties, phase rule, chemical equilibria and kinetics, pH and buffers, conductance, and chemical/instrumental methods of analysis.

10%

Part I — Inorganic chemistry

Atomic structure, periodic table and classification of elements, chemical bonds, oxidation and reduction, and detailed group chemistry.

Part I — Radioactivity, nuclear energy, and environmental chemistry

Radioactivity, nuclear reactions, atomic energy, and elementary environmental chemistry.

12%

Part I — Organic chemistry and aromatic substitution

Aliphatic, aromatic, and heterocyclic compounds; synthesis and properties; conformation, stereochemistry, and optical activity; nucleophilic, electrophilic, and free-radical reactions; aromatic and heterocyclic substitution.

Part I — Industrial products and waste

Principles of manufacturing common organic and inorganic industrial products and disposal of industrial wastes.

15%

Part II — Reactivity and reaction mechanism

Acids, bases, nucleophiles, electrophiles; hard and soft nucleophiles and electrophiles; molecular and frontier orbitals (HOMO and LUMO); kinetics and energetics; solvolytic reactions; ambident nucleophiles; multicentre addition; carbocation rearrangements.

10%

Part II — Chirality, ORD/CD, and atropisomerism

Chirality, molecular dissymmetry, atomic and conformational asymmetry, circular birefringence and circular dichroism, Cotton effect, optical rotatory dispersion, optical purity, conformational analysis, and atropisomerism.

19%

Part II — Spectroscopy and chromatography

UV, IR, Raman, ESR, 1H and 13C NMR, and mass spectrometry (principles and applications); chromatographic techniques, including principles, applications, advantages, and disadvantages.

Part II — Natural products and dyes

Carbohydrates and polysaccharides, starch, cellulose, amino acids, proteins, vitamins, hormones, antibiotics, alkaloids, and dyes.

How to Pass the BCS Written Chemistry Exam

What You Need to Know

Passing score: 50% aggregate on the 900-mark written examination (BPSC official page); per-paper minima also apply as set by BPSC
Assessment: Two 100-mark parts (200 marks total). Part I covers gas laws and thermodynamics, electrochemistry, colligative properties and phase rule, equilibria and kinetics, pH and buffers, conductance and instrumental analysis, atomic structure and group chemistry, radioactivity and environmental chemistry, organic compounds and substitution, and industrial manufacture and waste. Part II covers acids/bases/nucleophiles/electrophiles, HSAB and frontier orbitals, reaction mechanism, chirality and ORD/CD, atropisomerism, UV/IR/Raman/ESR/NMR/MS, chromatography, and carbohydrates, proteins, vitamins, hormones, antibiotics, alkaloids, and dyes. Official answers are descriptive. This page is a free English MCQ study adaptation.
Time limit: 4 hours (duration used for BPSC 200-mark written papers; confirm the current examination routine)
Exam fee: Tk. 200 general (50th BCS); Tk. 50 for ethnic minority, persons with disabilities, and third-gender categories; no separate written-stage fee. Confirm the live circular.

Keys to Passing

Work through all 100 available questions
Review every answer and explanation
Track weak areas and revisit them
Use our AI tutor for tough concepts

BCS Written Chemistry Study Tips from Top Performers

1Weight revision 50/50 to Part I and Part II; do not skip spectroscopy, chromatography, or natural products in Part II.

2Practise fully worked calculations for gas laws, ΔG = ΔH − TΔS, Nernst, colligative properties, first- and second-order half-lives, Kc, pH/buffers, Faraday electrolysis, and optical purity.

3For mechanisms, name the intermediate (carbocation, carbanion, radical) and whether the step is SN1, SN2, E1, E2, or a named rearrangement.

4For spectroscopy, memorize characteristic IR stretches, NMR splitting (n+1), the nitrogen rule, and which transitions appear in UV versus ESR.

5Use this MCQ bank to lock facts and numbers, then write timed descriptive answers; the official paper is not multiple choice.

Frequently Asked Questions

Is the official BCS Chemistry paper multiple choice?

No. BPSC Chemistry (subject code 531) is a 200-mark descriptive written paper in two 100-mark parts. This bank is an English-language MCQ study adaptation, not an official translation, format simulation, or substitute for handwriting answers.

How is the Chemistry syllabus split?

Part I (100 marks) covers physical chemistry and analysis, inorganic chemistry, radioactivity and environmental chemistry, organic compounds and substitution, and industrial manufacture and waste. Part II (100 marks) covers advanced physical, inorganic, and organic topics including HSAB and frontier orbitals, chirality and ORD/CD, atropisomerism, spectroscopy, chromatography, and natural products.

What is the written-stage pass mark?

The BPSC official page requires a 50% aggregate on the 900-mark written examination. Per-paper minima also apply as set by BPSC. Confirm the current circular.

How long is the Chemistry written paper?

Four hours is the duration used for BPSC 200-mark written papers in longstanding sitting practice. Confirm the timetable on the current examination routine.

Is there a separate fee for the written Chemistry paper?

No separate written or viva fee is published. The BCS application fee for the 50th cycle is reported as Tk. 200 general and Tk. 50 for ethnic minority, persons with disabilities, and third-gender categories. Confirm the live circular on BPSC Teletalk.

Who sits post-related Chemistry?

Technical/professional cadre candidates, and dual-cadre applicants, sit a 200-mark post-related subject. Chemistry (code 531) is that paper when it is the nominated subject. General-cadre candidates sit General Science & Technology instead of a post-related paper.

In what language is this practice bank?

The official BCS written examination may be answered in Bangla or English as permitted by BPSC. This bank is an original English-language MCQ study adaptation of the Chemistry syllabus, not an official BPSC paper or translation.

100+ Free BCS Written Chemistry Practice Questions

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