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Chemistry · Class 12 Science

Assam Ahsec Class 12 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.

2018–2026
Years of papers
8
Total Papers
8
Real Board Papers
0
Sample papers
274
Real-paper Q & A
0
Sample-paper Q & A

Real board-paper questions available, by year

—2026Paper not yet available
37 Q2025complete
30 Q2024complete
30 Q2023complete
57 Q2022complete
—2021Exam cancelled (COVID-19)
30 Q2020complete
30 Q2019complete
30 Q2018complete

2026 — Paper not yet available: This year’s exam was held, but neither AHSEC’s official site nor any source we check has published the question paper yet. We publish only a paper we can verify against a real printed original — this one will appear here once it is.

2021 — Exam cancelled (COVID-19): AHSEC cancelled the HS Final (Class-12) examination in 2021 due to COVID-19; no annual question paper was conducted or printed that year, so none exists to publish. Results were declared using a formula based on HSLC marks, institutional practicals, and internal assessment.

AHSEC Higher Secondary (HS) Final Examination 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
30
Duration
180 min
Sections
4

The marks / questions / duration above are the official exam pattern. We currently have 30 of this paper’s questions (100% of the full paper), with 30 fully solved. Questions we couldn’t yet extract or verify are held — never shown as complete.

Sections & marks

SectionTypeQuestionsMarks eachTotal
ASection Asubjective818
BSection Bsubjective10220
CSection Csubjective9327
DSection Dsubjective3515
Total3070

The question paper

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

Board Examination

Chemistry

AHSEC Higher Secondary (HS) Final Examination 2026 · Set ANNUAL

Series/Set: ANNUALRoll No. ________
Time Allowed: 3 hoursMaximum Marks: 70

General Instructions

  1. This question paper contains 30 questions divided into 4 sections — A, B, C, D.
  2. Section A comprises 8 questions of 1 mark each (subjective).
  3. Section B comprises 10 questions of 2 marks each (subjective).
  4. Section C comprises 9 questions of 3 marks each (subjective).
  5. Section D comprises 3 questions of 5 marks each (subjective).

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

Section A

subjective · 1 mark each · 8 of 8 shown

Q1.
Give an example of liquid in solid solution.
[1]
Q2.
What is the relation between standard electrode potential and reducing power?
[1]
Q3.
Which of the first row transition elements shows the highest oxidation state?
[1]
Q4.
Choose the correct answer : The distribution of hybrid orbitals in dsp^2 hybridization is
  • (a) tetrahedral
  • (b) square planar
  • (c) trigonal pyramidal
[1]
Q5.
What is the name of iodine-containing hormone whose deficiency causes goitre?
[1]
Q6.
What is the name of the following reaction? RCN + SnCl2 + HCl --(H3O+)--> RCHO
[1]
Q7.
Why is thionyl chloride preferred to prepare acid chloride from carboxylic acid?
[1]
Page 1 of 5
Q8.
Write the name of the reagent used in the following reaction : >C=O --(?)--> >CH2 + H2O
[1]
Section B

subjective · 2 marks each · 10 of 10 shown

Q1.
What is Raoult's law? Give an example of non-ideal solution.
[2]
Q2.
Why does para-nitrophenol possess higher boiling point than ortho-nitrophenol?
[2]
Q3.
State the variation of conductivity and molar conductivity of acetic acid with dilution.
[2]
Q4.
Explain why Cu+ compounds are colourless, but Cu++ compounds are coloured.
[2]
Q5.
What do you mean by order of a reaction? What is the unit of rate constant of first-order reaction? (1+1=2)
[2]
Q6.
How will you prepare ethyl fluoride from ethyl bromide?
[2]
Q7.
Complete the following reactions giving major products only (any two) : (i) 4-(hydroxymethyl)phenol + HCl --(Heat)--> ? (ii) 1-methylcyclohexene + HI --> ? (iii) chlorobenzene + Na --(Ether)--> ?
[2]
Page 2 of 5
Q8.
Arrange the following in increasing order as mentioned in the brackets (any two) : (i) C6H5NH2, NH3, C2H5NH2, (C2H5)2NH [Order of basicity] (ii) 2-methylphenol, phenol, 2-nitrophenol, 2,4-dinitrophenol [Order of acidity] (iii) HCOOH, CH3COOH, Cl2CHCOOH, CH2ClCOOH [Order of acidity]
[2]
Q9.
How will you distinguish 1°, 2° and 3° alcohols by Lucas reagent?
[2]
Q10.
Write the formulas of the following coordination compounds (any two) : (a) Tetraamminediaquacobalt(III) chloride (b) Tris(ethane-1,2-diamine) chromium(III) chloride (c) Iron(III) hexacyanoferrate(II)
[2]
Section C

subjective · 3 marks each · 9 of 9 shown

Q1.
Answer either (a) and (b) : (a) Write the name of two essential and two non-essential amino acids. (2) (b) What is peptide linkage? (1)
[3]
Q2.
Answer either (a) and (b) : (a) State the law of elevation of boiling point for dilute solution. (1) (b) 18 g of glucose is dissolved in 1 kg of water. At what temperature will water boil at 1.013 bar? Kb for water is 0.52 K kg mol^-1. (2)
[3]
Q3.
Answer either (a) : (a) State Nernst equation and from this equation, determine the equilibrium constant for the following reaction (1+2=3) : Zn(s) + Cu²+(aq) --> Zn²+(aq) + Cu(s)
[3]
Page 3 of 5
Q4.
How will you prepare K2Cr2O7 from Na2Cr2O7? State the oxidizing property of K2Cr2O7. (1+2=3)
[3]
Q5.
Answer either (a) and (b) : (a) Draw the structure of α-D(+) glucose. (1) (b) Draw the structure of D and L glyceraldehyde. (2)
[3]
Q6.
What do you mean by primary battery and secondary battery? State the function of secondary battery.
[3]
Q7.
Answer any three questions (1×3=3) : (a) Give one example of ideal solution. (b) Zinc compounds are colourless. Explain why. (c) What is the cause of low boiling point of ether than alcohol? (d) What is the reason of more stability of phenoxide ion?
[3]
Q8.
Answer either (a) and (b) : (a) Explain why aromatic amines are less basic than aliphatic amines. (2) (b) Write Hoffmann bromamide degradation reaction. (1)
[3]
Q9.
(a) Write the mechanism of any one of the following reactions (2) : (i) Dehydration of alcohol (ii) Acylation of amine ; (b) Which one of the following will undergo SN1 reaction? (1) : (i) (CH3)3CBr (ii) CH3CH2Br
[3]
Page 4 of 5
Section D

subjective · 5 marks each · 3 of 3 shown

Q1.
Answer either (a) : (a) Derive the integrated rate equation of first-order reaction. A first-order reaction is found to have a rate constant k = 5.5×10^-14 s^-1. Find the half-life of the reaction. (3+2=5)
[5]
Q2.
Answer either (a), (b) and (c) : (a) How will you account for the acidity of α-hydrogen atom in aldehyde and ketone? (1) (b) State aldol condensation reaction. (2) (c) How will you prepare CH3COOH using Grignard reagent? (2)
[5]
Q3.
Answer either (a) and (b) : (a) State Werner's theory of coordination compounds. (3) (b) Explain the formation of [Co(NH3)6]³+ from VBT. (2)
[5]
Page 5 of 5