CBSE Class 12 Chemistry Question Paper 2026 (Set 3 - 56/3/3) with Solutions is now available here for download. CBSE conducted the Class 12 Chemistry examination on February 28, 2026, from 10:30 AM to 1:30 PM.
CBSE Class 12 Chemistry paper is of total 100 marks out of which 70 marks are allocated to the theory paper and 30 marks are for practical examination.
The theory paper consists of 33 questions divided into five sections:
- Section A contains Multiple Choice Questions (MCQs),
- Section B contains Very Short Answer Type (VSA) Questions,
- Section C contains Short Answer Type (SA) Questions,
- Section D contains Case-Study based Questions,
- Section E contains Long Answer (LA) Type Questions.
All sections are compulsory.
CBSE Class 12 Chemistry Question Paper 2026 (Set 3 - 56/3/3) with Solution PDF
| CBSE Official PDF | CD PDF | CD PDF with Solutions |
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| Download official PDF 0.65 MB | Download Collegedunia PDF 0.46 MB | Download solutions PDF 0.55 MB |
CBSE Class 12 Chemistry 2026 Set 3 (56/3/3) Questions with Solutions
According to Werner’s theory, the primary valencies of the central metal atom :
The oxidation number of Pt in [Pt(en)2Cl2]2+ is :
Which of the following product is formed when salicylic acid is treated with \(\mathrm{(CH_3CO)_2O}\) in the presence of acid ?
- (A)
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- (B)
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- (C)
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- (D)
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Which reagent is used to distinguish between primary, secondary and tertiary amines ?
On electrolysis of very dilute aqueous solution of NaCl using platinum electrodes :
The correct order of decreasing basic strength in aqueous solution of the following is :
The mole fraction of a solute in 2.0 molal aqueous solution is :
Which of the following transition metals shows +1 and +2 oxidation states ?
On hydrolysis, which of the following carbohydrates gives only \(\mathrm{\beta}\)-glucose ?
Consider the following compounds : Chlorobenzene (I), 2,4,6-trinitrochlorobenzene (II), 2,4-dinitrochlorobenzene (III), 4-nitrochlorobenzene (IV). The correct order of increasing ease of nucleophilic substitution reactions of these compounds is :
The half-life periods of decomposition of \(\mathrm{NH_3}\) for different initial pressures are given below :
The order of the reaction is :
1 mole of liquid A and 2 moles of liquid B make a solution having a total vapour pressure 40 torr. The vapour pressure of pure A and pure B are 30 torr and 45 torr respectively. The above solution :
Assertion (A): Ethers have lower boiling points than the boiling points of alcohols.
Reason (R): This is due to the presence of hydrogen bonding in alcohols.
Assertion (A): Transition metals show their highest oxidation state with oxygen.
Reason (R): The ability of oxygen to form multiple bonds to metals.
Assertion (A): Monobromination of aniline can be conveniently done by protecting the amino group by acetylation.
Reason (R): Acetylation increases the activation effect of the amino group.
Assertion (A): Order of reaction is applicable to elementary as well as complex reactions.
Reason (R): For a complex reaction, molecularity has no meaning.
For a reaction A + B → Products, the rate law is \(\mathrm{Rate = k[A][B]^{3/2}}\). Write the overall order of the reaction. Can this reaction be an elementary reaction ? Give reason in support of your answer.
For the compound having molecular formula C\(_4\)H\(_9\)Br, write : (a) the isomer which is most reactive towards SN1 displacement. (b) the isomer which, on reacting with Na metal in the presence of dry ether, gives 2,5-Dimethylhexane.
Write IUPAC names of the following compounds :
(i) \( \mathrm{[PtCl_2(en)_2]SO_4} \)
(ii) \( \mathrm{(NH_4)_2[CoF_4]} \)
Define the following terms with a suitable example in each case :
(i) Ambidentate ligand
(ii) Double salt
How do you explain the following ?
(a) Presence of an aldehyde group in glucose
(b) Presence of a primary alcoholic group in glucose
Explain why, on addition of 1 mol of KCl to 1 litre of water, the boiling point of water increases, while the addition of 1 mol of methyl alcohol to 1 litre of water decreases the boiling point.
State Kohlrausch's law of independent migration of ions. With the help of a curve, explain why it is not easy to determine \(\Lambda_m^\circ\) for weak electrolytes by extrapolating the concentration--molar conductivity curve, as it is for strong electrolytes.
An antifreeze solution is prepared by dissolving 31 g of ethylene glycol (Molar mass = 62 g mol\(^{-1}\)) in 600 g of water. Calculate the freezing point of the solution. (K\(_f\) for water = 1.86 K kg mol\(^{-1}\))
Answer the following questions about the complexes \(\mathrm{[NiCl_4]^{2-}}\) and \(\mathrm{[Ni(CN)_4]^{2-}}\) :
(i) Write the hybridization involved in each case.
(ii) Which of them is the inner orbital complex and which one is the outer orbital complex ?
(iii) Compare their magnetic behaviour. [Atomic number : Ni = 28]
(i) Name two coordination compounds which are important in biological systems. (ii) What is meant by chelate effect ? Give an example. (iii) Why are low spin tetrahedral complexes rarely formed ?
How will you obtain the following from aniline ? Write the chemical equations involved :
(a) Sulphanilic acid
(b) 2,4,6-Tribromoaniline
(c) Acetanilide
An organic compound (A) with molecular formula \(\mathrm{C_3H_5N}\) on reaction with \(\mathrm{C_6H_5MgBr}\) followed by hydrolysis, gives a compound (B). Compound (B) forms an orange-red precipitate with 2,4-DNP reagent and does not give iodoform test. It neither reduces Tollens' or Fehling's reagent nor does it decolourise bromine water. On drastic oxidation with chromic acid it gives a carboxylic acid (C) having molecular formula \(\mathrm{C_7H_6O_2}\). Identify the compounds (A), (B) and (C). Write the reactions of compound (A) with \(\mathrm{C_6H_5MgBr}\) followed by hydrolysis to give compound (B).
The half-life period of a radioactive element is \(1.5 \times 10^{10}\) years. Calculate the time in which the activity of the element is reduced to 75% of its original value. \[ \text{Given : } \log 2 = 0.30,\; \log 3 = 0.48,\; \log 4 = 0.60 \]
Give reasons for the following :
(a) Haloalkanes react with KCN to form alkyl cyanides, while with AgCN they form isocyanides.
(b)
(c) Grignard reagents should be prepared under anhydrous conditions.
Living systems are made up of various complex biomolecules like carbohydrates, proteins, nucleic acids, lipids, etc. Proteins and carbohydrates are essential constituents of our food. In addition, some simple molecules like vitamins and mineral salts also play an important role in the functions of organisms. All proteins are polymers of \(\mathrm{\alpha}\)-amino acids. Proteins can be classified into two types on the basis of their molecular shape — Fibrous and Globular proteins. Vitamins are accessory food factors required in the diet. They are classified as fat-soluble and water-soluble. Deficiency of vitamins leads to many diseases. Nucleic acids are the polymers of nucleotides which in turn consist of a base, a pentose sugar and phosphate moiety. There are two types of nucleic acids — DNA and RNA. Nucleic acids are responsible for the transfer of characters from parents to offsprings.
Write the name of basic building units of proteins and nucleic acids. How can you differentiate between Fibrous and Globular proteins on the basis of their structures ?
What products would be formed when a nucleotide from DNA containing thymine is hydrolyzed ?
Write one structural difference between DNA and RNA.
Give one example each of a fat-soluble vitamin and a water-soluble vitamin.
Name the reagents used in the following reactions : (i) Oxidation of a primary alcohol to aldehyde (ii) Oxidation of a primary alcohol to carboxylic acid
Write the reaction involved in Kolbe's reaction.
Why are tertiary alcohols resistant to oxidation ?
Write the products of the following reaction : \[ (CH_3)_3C-O-C_2H_5 \xrightarrow{HI} ? \]
Answer the following: \[ (a)(i)\;\text{Write the product(s) when:} \] \[ (I)\;\text{One mol of ethanal is treated with }1\text{ mol of }CH_3OH\text{ in the presence of dry }HCl\text{ gas.} \] \[ (II)\;\text{Benzaldehyde is treated with conc. }NaOH. \] \[ (III)\;\text{Ethanoic acid is heated in the presence of }P_2O_5. \] \[ (a)(ii)\;\text{Write a simple chemical test to distinguish between ethanal and propanal.} \] \[ (a)(iii)\;\text{Write the name of the reagent to transform allyl alcohol to propenal.} \]
Write the product(s) when : (I) One mol of ethanal is treated with 1 mol of \(CH_3OH\) in the presence of dry HCl gas. (II) Benzaldehyde is treated with conc. NaOH. (III) Ethanoic acid is heated in the presence of \(P_2O_5\).
(i) Draw the structure of the semicarbazone of acetone.
(ii) Why are \( \alpha \)-hydrogen atoms of aldehydes and ketones acidic in nature ?
(iii) Arrange the following compounds in increasing order of their reactivity towards HCN :
\( \mathrm{CH_3COCH_3,\ CH_3CHO,\ (CH_3)_3C-CO-CH_3} \)
(iv) Write the reaction involved in Etard reaction.
(v) Write the product when \( \mathrm{C_6H_{11}-CHO} \) reacts with Zn(Hg)/conc. HCl.
Answer the following: \[ (a)(i)\;\text{Calculate the electrode potential of a half-cell for zinc electrode dipping in }0.01M\;ZnSO_4\text{ solution at }25^\circ C. \] \[ E^\circ_{Zn^{2+}/Zn}=-0.76V,\quad \log 10=1 \] \[ (a)(ii)\;\text{Write anode, cathode and overall reaction involved in dry cell.} \] \[ (a)(iii)\;\text{Equilibrium constant }(K_c)\text{ is related to }E^\circ_{\text{cell}},\text{ but not to }E_{\text{cell}}.\text{ Why?} \]
(i) The conductivity of 0.001 M solution of acetic acid is \( 3.905 \times 10^{-5} \) S cm\(^{-1}\). Calculate its molar conductivity and degree of dissociation (\(\alpha\)).
Given : \( \lambda^\circ_{\mathrm{CH_3COO^-}} = 40.9 \) S cm\(^2\) mol\(^{-1}\)
\( \lambda^\circ_{\mathrm{H^+}} = 349.6 \) S cm\(^2\) mol\(^{-1}\)
(ii) Give reasons for the following :
(I) Why does a mercury cell deliver a constant voltage for its entire life ?
(II) Why is it necessary to use salt bridge in a galvanic cell ?
Answer the following: \[ (a)(i)\;\text{Describe giving reason which one of the following pairs has the property indicated:} \] \[ (I)\;Fe\text{ or }Cu-\text{higher melting point} \] \[ (II)\;Ti^{3+}\text{ or }Sc^{3+}-\text{coloured in aqueous solution} \] \[ (III)\;Cr\text{ or }Zn-\text{higher third ionisation enthalpy} \] \[ (a)(ii)\;\text{Write the ionic equations for the oxidizing action of }MnO_4^-\text{ in acidic medium with:} \] \[ (I)\;Fe^{2+}\text{ ion} \] \[ (II)\;I^-\text{ ion} \]
A black-brown coloured solid (A) when fused with KOH in the presence of air, produces a dark green coloured compound (B) which on electrolytic oxidation in alkaline medium gives a dark purple coloured compound (C). Identify (A), (B) and (C). Write the reactions involved.
\[ \text{What happens when an acidic solution of the green compound }(B)\text{ is allowed to stand for some time? Also write the equation involved. What is this type of reaction called?} \]
CBSE Class 12 Chemistry Paper Structure
| Question Type | Description |
|---|---|
| Very Short Answer | 1–2 line answers, definitions, or simple equations |
| Short Answer | Explanations, derivations, or numerical problems |
| Long Answer | Detailed answers, reaction mechanisms, or calculations |
| Case-based / Integrated | Questions based on a given situation may include calculations or reasoning |
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