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Chemistry · Class 11 Science

Bihar Bseb Class 11 Chemistry — Real Previous-Year Papers

with complete answers

Real previous-year board papers, year by year — the official exam pattern, the full question paper, and every question solved the concept-first way. Distinct from the chapter-wise textbook bank.

2022–2026
Years of papers
5
Total Papers
5
Real Board Papers
0
Sample papers
417
Real-paper Q & A
0
Sample-paper Q & A

Real board-paper questions available, by year

—2026Paper not available
96 Q2025complete
96 Q2024complete
—2023Paper not available
—2022Paper not available
—2021Paper not available
—2020Paper not available
—2019Paper not available

2026 — Paper not available: The Bihar Board (BSEB) held the Class-XI (Intermediate 1st Year) Annual Examination this year, but no verified question paper for this subject is available from the sources we check — the official archive and the public past-paper archives. We publish only a paper we can verify against a real printed original, so we show none rather than an unconfirmed copy.

2023 — Paper not available: The Bihar Board (BSEB) held the Class-XI (Intermediate 1st Year) Annual Examination this year, but no verified question paper for this subject is available from the sources we check — the official archive and the public past-paper archives. We publish only a paper we can verify against a real printed original, so we show none rather than an unconfirmed copy.

2022 — Paper not available: The Bihar Board (BSEB) held the Class-XI (Intermediate 1st Year) Annual Examination this year, but no verified question paper for this subject is available from the sources we check — the official archive and the public past-paper archives. We publish only a paper we can verify against a real printed original, so we show none rather than an unconfirmed copy.

2021 — Paper not available: The Bihar Board (BSEB) held the Class-XI (Intermediate 1st Year) Annual Examination this year, but no verified question paper for this subject is available from the sources we check — the official archive and the public past-paper archives. We publish only a paper we can verify against a real printed original, so we show none rather than an unconfirmed copy.

2020 — Paper not available: The Bihar Board (BSEB) held the Class-XI (Intermediate 1st Year) Annual Examination this year, but no verified question paper for this subject is available from the sources we check — the official archive and the public past-paper archives. We publish only a paper we can verify against a real printed original, so we show none rather than an unconfirmed copy.

2019 — Paper not available: The Bihar Board (BSEB) held the Class-XI (Intermediate 1st Year) Annual Examination this year, but no verified question paper for this subject is available from the sources we check — the official archive and the public past-paper archives. We publish only a paper we can verify against a real printed original, so we show none rather than an unconfirmed copy.

Bihar Board Intermediate 1st Year 2026 · Set ANNUAL

Real board examination

About this paper

The real Class-12 board examination held in 2026. Every question below is solved the concept-first way. Sample papers are labelled honestly — never shown as a past exam.

Total marks
70
Questions
48
Duration
195 min
Sections
3

The marks / questions / duration above are the official exam pattern. We currently have 96 of this paper’s questions (200% of the full paper), with 96 fully solved. Questions we couldn’t yet extract or verify are held — never shown as complete.

Sections & marks

SectionTypeQuestionsMarks eachTotal
Section A (Objective, Q1–70)Section Section A (Objective, Q1–70)Objective (MCQ) — answer any 35 of 70, on OMR35135
Section B — Short AnswerSection Section B — Short AnswerShort answer — answer any 10 of 2010220
Section B — Long AnswerSection Section B — Long AnswerLong answer (internal choice) — answer any 3 of 63515
Total4870

The question paper

The questions we hold for this paper, laid out by section. Solutions are on the Answers tab.

Board Examination

Chemistry

Bihar Board Intermediate 1st Year 2026 · Set ANNUAL

Series/Set: ANNUALRoll No. ________
Time Allowed: 3 hr 15 minMaximum Marks: 70

General Instructions

  1. This question paper contains 48 questions divided into 3 sections — Section A (Objective, Q1–70), Section B — Short Answer, Section B — Long Answer.
  2. Section Section A (Objective, Q1–70) comprises 35 questions of 1 mark each (Objective (MCQ) — answer any 35 of 70, on OMR).
  3. Section Section B — Short Answer comprises 10 questions of 2 marks each (Short answer — answer any 10 of 20).
  4. Section Section B — Long Answer comprises 3 questions of 5 marks each (Long answer (internal choice) — answer any 3 of 6).

Above is the official exam pattern. The questions printed below are those we currently hold for this paper.

Section A

Q1.
Which of the following is a chemical change ?
  • (a) Dissolution of common salt in water
  • (b) Heating a platinum wire
  • (c) Dissolution of sodium metal in water
  • (d) Heating of water
[1]
Q2.
The law of multiple proportion was propounded by
  • (a) Dalton
  • (b) Berzelius
  • (c) Graham
  • (d) Priestley
[1]
Q3.
"At the same temperature and pressure, equal volumes of all gases contain equal number of molecules." This statement is based on which law ?
  • (a) Berzelius' law
  • (b) Avogadro's hypothesis
  • (c) Graham's law
  • (d) Charles' law
[1]
Q4.
A group of 6.022 × 10^23 particles is called
  • (a) Mole
  • (b) Atomic mass unit
  • (c) Graham's law
  • (d) Charles' law
[1]
Q5.
The total number of moles in 720 gm of water is
  • (a) 4
  • (b) 10
  • (c) 40
  • (d) 72
[1]
Q6.
Which of the following is the molecular formula of washing soda ?
  • (a) NaOH
  • (b) Na2CO3.10 H2O
  • (c) Na2CO3
  • (d) NaHCO3
[1]
Page 1 of 11
Q7.
The necessary volume of oxygen that should be required to convert 10 ml of SO2 to SO3 by complete oxidation is (a) 10 ml (b) 20 ml (c) 30 ml (d) 5 ml
[1]
Q8.
If atomic mass of an element is 23 and its atomic number is 11, then the number of neutrons in an atom of the element would be (a) 23 (b) 12 (c) 11 (d) 34
[1]
Q9.
If the number of an orbit is expressed by n, then the total number of orbitals in it is (a) n (b) 2n (c) n² (d) 2n²
[1]
Q10.
The shape of s-orbital is (a) Spherical (b) Dumb-bell (c) Double dumb-bell (d) None of these
[1]
Q11.
Atoms having same atomic number but different mass numbers are called (a) Polymers (b) Isomers (c) Isotopes (d) Isobars
[1]
Q12.
The volume of 4.4 gm of CO2 at standard temperature and pressure is (a) 22.4 L (b) 11.2 L (c) 5.6 L (d) 2.24 L
[1]
Q13.
The value of gas constant in equation of state for an ideal gas PV = nRT depends upon (a) Nature of the gas (b) Pressure of the gas (c) Temperature of the gas (d) Unit of measurement
[1]
Q14.
"The real volume of gas molecules is negligible." The statement is in accordance with (a) Avogadro's hypothesis (b) Kinetic theory (c) Boyle's law (d) Charles' law
[1]
Q15.
A liquid is in equilibrium with its vapour at its boiling point. On an average of the molecules in two phases which of the following is equal ? (a) Potential energy (b) Total energy (c) Kinetic energy (d) Intermolecular forces
[1]
Q16.
The relation between enthalpy and internal energy is (a) ΔE = ΔH + PΔV (b) ΔH = ΔE + PΔV (c) ΔH = − ΔE − PΔV (d) ΔH = ΔE + VΔP
[1]
Page 2 of 11
Q17.
Which of the following is an extensive property ? (a) Enthalpy (b) Temperature (c) Pressure (d) Density
[1]
Q18.
For the reaction, C(s) + O2(g) → CO2(g), which of the following is correct ? (a) ΔH = ΔE (b) ΔH < ΔE (c) ΔH > ΔE (d) None of these
[1]
Q19.
The heat of neutralization of a strong acid and strong base is (a) 13.7 kcal (b) Greater than 13.7 kcal (c) Less than 13.7 kcal (d) None of these
[1]
Q20.
Which of the following is a Lewis base ? (a) HCl (b) HNO3 (c) HF (d) NH3
[1]
Q21.
The conjugate base of HBr is (a) H2Br^+ (b) H^+ (c) Br^- (d) Br^+
[1]
Q22.
Which of the following is the strongest base ? (a) AsH3 (b) NH3 (c) PH3 (d) SbH3
[1]
Q23.
Who enunciated the law of mass action ? (a) Gulberg and Waage (b) Bodenstein (c) Berthelot (d) Graham
[1]
Q24.
For which of the following reactions Kp > Kc ? (a) N2(g) + 3H2(g) ⇌ 2NH3(g) (b) H2(g) + I2(g) ⇌ 2HI(g) (c) PCl3(g) + Cl2(g) ⇌ PCl5(g) (d) 2SO3(g) ⇌ 2SO2(g) + O2(g)
[1]
Q25.
The pH of an aqueous solution is 4.0, the value of its pOH would be (a) 4.0 (b) 6.0 (c) 8.0 (d) 10.0
[1]
Q26.
An aqueous solution of NH4Cl is (a) Acidic (b) Alkaline (c) Neutral (d) None of these
[1]
Q27.
In which of the following oxidation number of oxygen is maximum ? (a) H2O2 (b) K2O (c) KO2 (d) O2F2
[1]
Page 3 of 11
Q28.
Which of the following is a redox reaction ? (a) NaBr + HCl → NaCl + HBr (b) HBr + AgNO3 → AgBr + HNO3 (c) H2 + Br2 → 2HBr (d) Na2O + H2SO4 → Na2SO4 + H2O
[1]
Q29.
In which of the following compounds oxidation number of Cl is + 5 ? (a) HClO4 (b) HClO2 (c) HClO3 (d) HClO
[1]
Q30.
Which of the following acts both as oxidising as well as reducing agent ? (a) H2S (b) SO3 (c) SO2 (d) H2SO4
[1]
Q31.
The reaction, Fe³+ + 1e → Fe²+ is (a) Oxidation (b) Reduction (c) Both oxidation and reduction (d) None of these
[1]
Q32.
Which of the following is a non-polar compound ? (a) HCl (b) CH2Cl2 (c) CHCl3 (d) CCl4
[1]
Q33.
In which of the following compounds both ionic and covalent bonds are present ? (a) CH4 (b) H2 (c) KCN (d) KCl
[1]
Q34.
The hybridization of carbon in CO2 is (a) sp (b) sp² (c) sp³ (d) sp³ d
[1]
Q35.
Which of the following is not a linear molecule ? (a) CO2 (b) BeCl2 (c) C2H2 (d) H2S
[1]
Q36.
Which of the following has the largest bond angle ? (a) H2O (b) CO2 (c) NH3 (d) CH4
[1]
Q37.
Which of the following compounds can form hydrogen bond ? (a) CH4 (b) H2O (c) NaCl (d) CHCl3
[1]
Q38.
The number of unpaired electrons in a molecule of liquid O2 is (a) 1 (b) 2 (c) 3 (d) 0
[1]
Page 4 of 11
Q39.
Who gave the law of octave ? (a) Dobereiner (b) Newlands (c) Lothar Mayer (d) Mendeleev
[1]
Q40.
The elements in the right hand side in periodic table are (a) Metals (b) Non-metals (c) Metalloids (d) Transition elements
[1]
Q41.
Which of the following is a fundamental property of elements ? (a) Atomic weight (b) Molecular weight (c) Atomic number (d) Density
[1]
Q42.
Which of the following is the most electronegative element in periodic table ? (a) N (b) O (c) Cl (d) F
[1]
Q43.
Which of the following ions has the largest size ? (a) Na^+ (b) Mg²+ (c) O²- (d) F^-
[1]
Q44.
Transition metals have incomplete (a) s-orbital (b) p-orbital (c) d-orbital (d) f-orbital
[1]
Q45.
Which of the following metals does not liberate hydrogen gas on reaction with dil. HCl ? (a) Zn (b) Cu (c) Na (d) Mg
[1]
Q46.
Which of the following oxides reacts with dil. H2SO4 to form hydrogen peroxide ? (a) MgO (b) Na2O (c) Na2O2 (d) Fe2O3
[1]
Q47.
How many neutrons are there in protium ? (a) 0 (b) 1 (c) 2 (d) 3
[1]
Q48.
Solvay's process is used for the manufacture of which of the following ? (a) Na2CO3 (b) NaOH (c) CaCl2 (d) All of these
[1]
Q49.
Which of the following is limestone ? (a) CaO (b) Ca(OH)2 (c) CaCO3 (d) None of these
[1]
Page 5 of 11
Q50.
Which of the following has highest bond energy ? (a) C − C (b) Si − Si (c) Sn − Sn (d) Ge − Ge
[1]
Q51.
Which of the following is inorganic benzene ? (a) Borax (b) Graphite (c) Borazine (d) Pyridine
[1]
Q52.
In which of the following + 2 oxidation state is the most stable ? (a) C (b) Ge (c) Pb (d) Si
[1]
Q53.
In laboratory first organic compound was synthesised by (a) Kekule (b) Hennel (c) Wöhler (d) Liebig
[1]
Q54.
The functional group of acetone is (a) − OH (b) − COOH (c) >C=O (d) − CHO (−C(=O)H)
[1]
Q55.
Hydrocarbons containing single bond are called (a) Unsaturated hydrocarbon (b) Saturated hydrocarbon (c) Aromatic hydrocarbon (d) None of these
[1]
Q56.
The functional group present in carboxylic acids is (a) − CHO (b) − CO − (c) − COOH (d) − COOR
[1]
Q57.
Which of the following is the functional group of secondary amine ? (a) − NH2 (b) − NH − (c) − N< (−N−) (d) None of these
[1]
Q58.
The IUPAC name of CH3COOH is (a) Acetic acid (b) Formic acid (c) Ethanoic acid (d) Methanoic acid
[1]
Q59.
The IUPAC name of CH3−CH(OH)−CH3 is (a) Propan-1-ol (b) Propan-2-ol (c) n-propyl alcohol (d) Isopropyl alcohol
[1]
Q60.
An isomer of ethanol is (a) Methanol (b) Dimethyl ether (c) Diethyl ether (d) Ethylene glycol
[1]
Page 6 of 11
Q61.
Which of the following is optically active ? (a) d-tartaric acid (b) Mesotartaric acid (c) dl-tartaric acid (d) None of these
[1]
Q62.
Which of the following exhibits geometrical isomerism ? (a) Propene (b) But-2-ene (c) But-1-ene (d) 2, 3-dimethylbut-2-ene
[1]
Q63.
Acetylene molecule is (a) Tetrahedral (b) Trigonal planar (c) Linear (d) None of these
[1]
Q64.
Which of the following is an electrophilic reagent ? (a) AlCl3 (b) ROH (c) NH3 (d) OH^-
[1]
Q65.
Which of the following is the most stable ? (a) CH3^+ (methyl cation) (b) CH3CH2^+ (ethyl cation) (c) CH3−CH^+−CH3 (isopropyl cation) (d) (CH3)3C^+ (tert-butyl cation)
[1]
Q66.
Which of the following is not a nucleophile ? (a) CN^- (b) CH3O^- (c) BF3 (d) NH3
[1]
Q67.
In organic compounds nitrogen can be estimated by which of the following methods ? (a) Kjeldahl method (b) Duma method (c) Both (A) and (B) (d) None of these
[1]
Q68.
The general molecular formula of an alkene is (a) CnH2n+2 (b) CnH2n (c) CnH2n+1 (d) CnH2n-2
[1]
Q69.
A compound containing −C≡C− group is an example compound (a) Ethane (b) Ethylene (c) Ethyne (d) Propene
[1]
Q70.
Which of the following prevents ultraviolet radiations from coming to earth's surface ? (a) Methane (b) Mist (c) Carbon dioxide (d) Ozone
[1]
Page 7 of 11
Section B

Q1.
Mention Dalton's atomic theory.
[2]
Q2.
What is atomic mass unit ?
[2]
Q3.
Mention the charge and mass of an electron.
[2]
Q4.
Define mass number.
[2]
Q5.
What is called surface tension ?
[2]
Q6.
Write Dalton's law of partial pressure.
[2]
Q7.
Write first law of thermodynamics.
[2]
Q8.
Define Bond energy.
[2]
Page 8 of 11
Q9.
What do you mean by equilibrium constant ?
[2]
Q10.
Define pH.
[2]
Q11.
Calculate oxidation number of Mn in the following: (a) KMnO4 (b) K2MnO4
[2]
Q12.
What is modern periodic law ? Explain.
[2]
Q13.
What are metalloids ? Give two examples.
[2]
Q14.
What is hydrogen bond ?
[2]
Q15.
Define electrovalent bond.
[2]
Q16.
Write the names and symbols of isotopes of hydrogen.
[2]
Q17.
Write the symbols and atomic numbers of group 2 elements.
[2]
Page 9 of 11
Q18.
What is asymmetric carbon atom ? Give an example.
[2]
Q19.
What is vital force theory ?
[2]
Q20.
What is Inductive effect ?
[2]
Section C

Q1.
Define empirical and molecular formulae and give the relation between them. How would you determine the empirical formula of a compound from the percentage composition of its elements ?
[5]
Q2.
Explain the defects of Rutherford's atomic theory.
[5]
Q3.
What is hybridization ? Explain sp, sp² and sp³ hybridization by giving examples.
[5]
Page 10 of 11
Q4.
Write chemical formulae of the following compounds: (i) Washing soda (ii) Baking soda (iii) Glauber's salt (iv) Plaster of Paris (v) Bleaching powder
[5]
Q5.
Write IUPAC names of the following: (i) CH3−CH2−CH(CH3)−CH(CH3)−CH3 (ii) CH3−C≡C−CH2−CH3 (iii) CH3−CH(Cl)−CH2Cl (iv) CH3COOH (v) CH3COOC2H5
[5]
Q6.
Write short notes on the following: (i) Substitution reaction (ii) Elimination reaction
[5]
Page 11 of 11