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NEET Chapter PYQs with Solutions

376 previous year questions from Chapter (NEET UG Chemistry) with answers and solutions. Numbered list, year tags, and one-tap solutions — built for serious JEE / NEET practice.

376 questionsChemistry2008–2026Answers + solutions

About Chapter PYQs

Chapter has 376 previous year questions in the Quantrex Academy NEET UG Chemistry bank. The 220 questions in this list come from NEET (220), spanning 2008 to 2026. Each question opens on its own page with the options, the correct answer and the worked solution where available.

Questions by year (this list)

  • 2026: 213
  • 2019: 3
  • 2012: 1
  • 2011: 2
  • 2008: 1

Chapter questions with solutions

1

Which of the following postulates of Dalton's atomic theory provides the direct theoretical basis for the law of conservation of mass?

NEET 2026 Solution View → 2

Consider the following five samples of substances: A. 88 g of CO_2 B. 96 g of O_2 C. 34 g of NH_3 D. 36 g of H_2O E. 40 g of Ne Which of the given samples contain an identical

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If the shortest wavelength of the Lyman series for a hydrogen atom is x , then the longest wavelength of the Paschen series for a He^ + ion is:

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What are the energy of the second Bohr orbit of Be^ 3+ and the radius of the third Bohr orbit of He^ + respectively? [Given: R_ H = 2.18 × 10^ -18 J, a_0 = 52.9 pm ]

NEET 2026 Solution View → 5

Consider the following electronic configurations of neutral atoms: A. [Ne] 3s^2 3p^4 B. [Ar] 3d^6 4s^2 C. [Kr] 4d^ 10 5s^2 D. [Xe] 4f^ 14 5d^ 10 6s^2 6p^2 E. [Ar] 3d^5 4s^1 Which

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Consider the following sequences of molecules and their associated properties: (I) CH_3Cl CH_2Cl_2 CHCl_3 : Dipole moment (II) H_2Te H_2S H_2O : Bond angle (III) CO CO_2 CO_3^ 2

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The potential energy profile for a hypothetical reaction X arrow Y is shown in the given figure. Based on the graph, what is the enthalpy change ( Δ H ) for this reaction?

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For a reversible gas-phase reaction, X(g) + Y(g) leftharpoons Z(g) the rate constant for the forward reaction is 82 times the rate constant for the backward reaction at 500 K. The

NEET 2026 Solution View → 9

Consider the following equilibrium for the synthesis of sulfur trioxide: 2SO_2(g) + O_2(g) leftharpoons 2SO_3(g) Δ H = -198 kJ mol^ -1 Which of the following conditions will favor

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Hydrogen sulfide ( H_2S ) is a weak diprotic acid that ionizes in two successive steps in an aqueous solution, with ionization constants K_ a_1 and K_ a_2 . If K_ eq represents

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What are the respective oxidation states of the underlined atoms in O F_2 , Li H , and K_2 Cr _2O_7 ?

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An analytical chemist needs to perform the following four separations: (I) Separation of a mixture of ether (b.p. 308 K ) and toluene (b.p. 384 K ) (II) Separation of two miscible

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Observe the given compounds I, II, and III. Identify the correct decreasing order of bond dissociation energy for the C-H bonds marked with an asterisk (*).

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The given flowchart illustrates various methods for the preparation of benzene. Identify the correct set of reagents A, B, and C required for these conversions.

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The skeletal structure of a cyclic hydrocarbon is shown in the figure above. Which of the following is the correct observation when this compound is shaken with aqueous bromine

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Based on the physical states of the solute and the solvent, identify the incorrect match from the following examples of solutions:

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Assuming complete dissociation of the electrolytes, which of the following aqueous solutions will freeze at the lowest temperature?

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A binary solution is prepared by mixing 2 moles of liquid P and 3 moles of liquid Q. At a certain temperature, the vapour pressures of pure P and pure Q are 120 mm Hg and 160 mm

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The molar conductivity of a 0.02 M solution of propanoic acid is 31.2 S cm^2 mol^ -1 . What is the percentage dissociation of the acid in this solution? [Given: Limiting molar

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A chemical reaction has a rate constant of 6.93 × 10^ -3 ~s^ -1 . How much time will it take for the reaction to be 93.75\% complete? (Given : 2 = 0.301 )

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Identify the set of coordination complexes in which all the species are diamagnetic in nature.

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Arrange the following coordination complexes in the increasing order of the wavelength of light absorbed by them: A. [Cr(NH_3)_6]^ 3+ B. [Cr(CN)_6]^ 3- C. [Cr(H_2O)_6]^ 3+ D.

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According to Werner's coordination theory, which of the following empirical formulations of platinum(IV) chloride with ammonia will exhibit the lowest molar conductance in aqueous

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Predict the major product 'Z' in the following sequence of reactions.

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Consider the three alkyl halides labelled as I, II, and III in the given figure. Which of the following represents the correct decreasing order of their reactivity towards an S_ N

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What is the total number of acyclic ether isomers (including both structural and stereoisomers) possible for the molecular formula C_5H_ 12 O ?

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Identify the major organic product formed in the following reaction.

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Identify the appropriate reagent 'X' to carry out the given chemical transformation.

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Identify the correct decreasing order of acidic strength for the following substituted carboxylic acids.

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An organic compound X ( C_6H_7N ) on treatment with NaNO_2 and dilute HCl at 273-278 K forms an intermediate Y . The intermediate Y is unstable in the dry state but can be

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The cyclic structure of D-(-)-fructose is known as a furanose structure. According to its structural representation, the furanose ring of fructose consists of:

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Arrange the following samples of oxygen gas ( O_2 ) in increasing order of the number of molecules present in them: (I) 1.6 g of O_2 (II) 22.4 L of O_2 at STP (III) 0.08 mol of

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1.12 g of solid potassium hydroxide (KOH) is added to 50 mL of a 0.25 M aqueous solution of H_2SO_4 . Assuming complete neutralization, the mass of the unreacted reactant left in

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If the energy of an electron in the first Bohr orbit of a hydrogen atom is -E , then the energy of an electron in the third Bohr orbit of a He^ + ion is:

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Based on the quantum mechanical model of the atom, match the quantum numbers in List I with their allowed values in List II. List I List II A Principal quantum number ( n ) I -l

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Observe the given structure of 1-buten-3-yne where specific bonds are labeled as 'a', 'b', 'c', and 'd'. Match the labeled bonds in List I with their corresponding nature in List

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Observe the given bar graph comparing the boiling points of the three isomers of nitrophenol. The noticeably lower boiling point of o -nitrophenol compared to its m - and p

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Identify the processes in which the entropy of the system decreases. A. Freezing of water to ice at 273 K . B. 2SO_ 2(g) + O_ 2(g) arrow 2SO_ 3(g) C. Mixing of two non-reacting

NEET 2026 Solution View → 39

For the reaction CO(g) + H_2O(g) leftharpoons CO_2(g) + H_2(g) , the equilibrium constant K_c is 4.0 at a specific temperature. If a reaction mixture contains 0.1 M of CO , 0.1 M

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For which of the following reversible reactions is the relationship K_p = K_c (RT)^ -1 correct?

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Which of the following mixtures is most suitably separated by the technique of sublimation?

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A saturated acyclic hydrocarbon with the molecular formula C_7 H_ 16 is found to have exactly one tertiary carbon atom and one quaternary carbon atom. What is the IUPAC name of

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Consider the organic molecule 2-methylbutane ( CH_3-CH(CH_3)-CH_2-CH_3 ). If a hydride ion ( H^- ) is removed from this molecule to generate a carbocation, removal from which

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At a constant temperature, the Henry's law constants ( K_H ) for four gases W, X, Y, and Z in water are 35 kbar , 0.15 kbar , 76 kbar , and 1.67 kbar respectively. The correct

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The given plot shows the variation of k versus (1)/(T) for two different chemical reactions, Reaction 1 and Reaction 2. Based on the graph, which of the following relations is

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The third ionization enthalpy of manganese ( Z=25 ) is exceptionally high, whereas that of iron ( Z=26 ) is comparatively lower. This contrast is best explained by the respective

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Which of the following ions possess a spin-only magnetic moment of approximately 2.83 BM ? A. V^ 3+ B. Co^ 2+ C. Ni^ 2+ D. Cu^ + E. Mn^ 3+ Choose the most appropriate answer from

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Observe the different pairs of isomeric coordination compounds described in List I. Match List I with the correct type of structural isomerism they represent in List II. List I

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(I) (II) (III) Consider the three substituted benzyl chlorides. Which of the following represents the correct decreasing order of their reactivity towards S_ N 1 solvolysis?

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An organic compound whose structure is shown above is treated with Lucas reagent (a mixture of concentrated HCl and anhydrous ZnCl_2 ) at room temperature. Which of the following

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To prepare Fehling's reagent for the identification of aliphatic aldehydes, aqueous copper sulphate is mixed with an alkaline solution of a complexing agent. This agent prevents

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A chemical analysis of an inorganic compound shows that it contains 40\% of element P , 30\% of element Q , and 30\% of element R by mass. If the respective atomic masses of P, Q

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Calculate the work done when 5 moles of an ideal gas expand isothermally and reversibly from a volume of 2 L to 20 L at 27^ ∘ C . (Given R = 8.314 J K^ -1 mol^ -1 )

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The osmotic pressure of an aqueous solution of urea (molar mass = 60 g mol^ -1 ) is 0.492 atm at 300 K . Assuming the density of the solution to be 1.0 g mL^ -1 and using R =

NEET 2026 Solution View → 55

A current of 1.93 A is passed through an aqueous solution of silver nitrate ( AgNO_3 ) for 500 seconds . What is the mass of silver deposited at the cathode? (Given: Molar mass of

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The rate constant of a decomposition reaction becomes ten times its initial value when the temperature is increased from 200 K to 250 K . Calculate the activation energy of the

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Identify the major products A and B formed in the following reaction sequence.

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Consider the following reaction: Identify the major organic products X and Y .

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Given below are certain basic radicals. Based on inorganic qualitative analysis, arrange them in increasing order of their group number. A. Zn^ 2+ B. Sr^ 2+ C. As^ 3+ D. NH_4^ +

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What is the mass of acetylene ( C_2H_2 ) gas produced when 32 g of a commercial sample of calcium carbide ( CaC_2 ), which is 75\% pure, reacts completely with an excess of water?

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The elements P , S , K , and Ca form stable ions to achieve the nearest noble gas configuration. Identify the smallest and the largest ions formed among them, respectively.

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Let x be the maximum number of electrons that can be accommodated in a particular subshell. Which of the following expressions correctly defines the azimuthal quantum number ( l )

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The stability of the lower oxidation state increases down a group in the p-block due to the inert pair effect. Based on this principle, which of the following oxides will act as

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Identify the correct count of σ -bonds, π -bonds, and lone pairs of electrons present in a molecule of aniline.

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Which of the following sets of molecules contains ONLY those species that violate the octet rule?

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A hypothetical reaction is observed to be non-spontaneous at low temperatures, but it becomes spontaneous when the temperature is raised significantly. Which of the following

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Which of the following pairs of chemical species consists entirely of Lewis acids?

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Identify the correct classification for the organic halogen compound shown:

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Identify the major product (P) formed in the given reaction.

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The reaction, CF_3CH_2OH + CH_3CH_2ONa arrow CF_3CH_2ONa + CH_3CH_2OH suggests that:

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A conductivity cell filled with 0.1 M HCl solution has a resistance of 50 Ω at 300 K . If the conductivity of 0.1 M HCl is 3.6 × 10^ -2 S cm^ -1 , what will be the conductivity of

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Assertion : p -Methoxyphenol is a weaker acid than m -methoxyphenol. Reason : The -OCH_3 group exerts a +I effect which destabilizes the conjugate base.

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In the lanthanoid series, the +3 oxidation state is the most characteristic and stable state in aqueous solutions, despite the large amount of energy required to remove three

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Consider the given reaction sequence and identify the final major product 'X'.

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An alcohol, whose structure is shown in the figure, is heated with concentrated hydroiodic acid (HI) to yield a major alkyl halide product via a substitution mechanism. What is

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What is the mass (in grams) of the hydrocarbon formed when 0.5 moles of sodium adipate is heated strongly with an excess of soda lime?

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Consider the following chemical reactions: (I) Benzamide Br_2, \ NaOH Product A (II) Benzamide [(ii) H_2O] (i) LiAlH_4 Product B (III) Phenyl isocyanide [(ii) H_2O] (i) LiAlH_4

NEET 2026 Solution View → 78

In Rutherford's scattering experiment, which specific observation led to the conclusion that the entire positive charge and most of the mass of the atom are densely concentrated

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For which of the following gaseous reactions is the change in enthalpy ( Δ H ) exactly equal to the change in internal energy ( Δ U ) at a constant temperature?

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For the gas-phase reaction X_2(g) + Y_2(g) leftharpoons 2XY(g) , the equilibrium concentrations of X_2 , Y_2 , and XY at 500 K are 0.01 mol L^ -1 , 0.01 mol L^ -1 , and 0.1 mol L^

NEET 2026 Solution View → 81

Consider the following redox reaction in an acidic medium: x MnO_4^ - + y C_2O_4^ 2- + z H^ + arrow x Mn^ 2+ + 2y CO_2 + (z)/(2) H_2O When the equation is correctly balanced using

NEET 2026 Solution View → 82

Which among the following alcohols will undergo acid-catalyzed dehydration most rapidly?

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Consider the four cyclic species labeled (I) to (IV) in the given figure. According to Huckel's rule, which of the following combinations correctly identifies ONLY the aromatic

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Assertion (A): Oxygen molecule ( O_2 ) is paramagnetic in nature. Reason (R): The molecular orbital electronic configuration of O_2 contains two unpaired electrons in its bonding

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The thermodynamic stability of a coordination compound in aqueous solution is quantitatively expressed by its overall formation constant ( β ). Among the given species, which

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Consider the chemical reaction shown in the given figure. Which of the following correctly identifies the major products P and Q?

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Identify the final major product [S] obtained in the following sequence of reactions: (i) LiAlH_4 , (ii) H_3O^+ [P] [Δ] conc. H_2SO_4 [Q] (i) B_2H_6 /THF, (ii) H_2O_2/OH^- [R] PCC

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An organic compound 'Y' has the structure shown in the figure. Compound 'Y' is treated with an alkaline solution of ammoniacal silver nitrate and heated. Which of the following

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Which of the following gas samples contains the same number of molecules as 3.4 g of ammonia ( NH_3 )?

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The atomic radii of the elements Na , Mg , Al , and Si are given in a random order as 118 pm , 143 pm , 160 pm , and 186 pm . Based on the periodic trend, which of the following

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Given below is an outline of the modern periodic table where four elements are marked as P, Q, R, and S. Match List I (the marked elements) with List II (their characteristic

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Consider a chemical reaction where the total enthalpy of the products is greater than the total enthalpy of the reactants. Which of the following statements are correct for this

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Consider the following two equilibrium reactions at a constant temperature: (i) CO(g) + 2H_2(g) leftharpoons CH_3OH(g) ; Equilibrium constant = K_1 (ii) 3CH_3OH(g) leftharpoons

NEET 2026 Solution View → 94

The dissociation of phosphorus pentachloride is an endothermic process: PCl_5(g) leftharpoons PCl_3(g) + Cl_2(g), Δ H > 0 According to Le Chatelier's principle, which of the

NEET 2026 Solution View → 95

During the titration of ammonium hydroxide (taken in a conical flask) against dilute hydrochloric acid, which indicator is most suitable and what is the colour change observed at

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Aniline (boiling point 184^ ∘ C ) is often purified from a crude mixture using steam distillation. Which of the following statements correctly describe the principles of this

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Identify the IUPAC name of the major product Y formed in the following reaction sequence.

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Calculate the mass of oxalic acid dihydrate needed to prepare 500 mL of a 0.02 M aqueous solution. (Molar mass of H_2C_2O_4 · 2H_2O = 126 g mol^ -1 )

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An electrolyte concentration cell consists of two identical metallic electrodes dipped in solutions of the same electrolyte but at different concentrations. Which of the following

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The initial rate of a chemical reaction, P + Q arrow Products , was measured at various initial concentrations of the reactants. The experimental data is provided in the

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The given figure displays the Arrhenius plots ( k vs (1)/(T) ) for two distinct chemical reactions, labeled as Reaction X and Reaction Y. Based on the provided graph, identify the

NEET 2026 Solution View → 102

An aqueous solution of potassium dichromate is orange in colour. On adding an alkali to this solution, the colour changes to yellow. This colour change is due to the formation of:

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Unlike transition metal complexes, the colors of lanthanoid(III) complexes are generally not affected by the nature of the ligands. The primary reason for this behavior is that:

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The oxidation states shown by Mn in the given reaction are : 2 MnO_4^ - + 3 Mn^ 2+ + 2 H_2O 5 MnO_2 + 4 H^ + A. +6 B. +4 C. +3 D. +7 E. +2 Choose the correct answer from the

NEET 2026 Solution View → 105

Which of the following ions or molecules acts as an ambidentate ligand in coordination compounds?

NEET 2026 Solution View → 106

Ethylenediaminetetraacetate ( EDTA^ 4- ) is a widely used ligand in coordination chemistry. Which of the following correctly describes its denticity and the nature of its donor

NEET 2026 Solution View → 107

Identify the major product R formed in the following reaction sequence: C_6H_5CH_2COOH [Δ] NH_3 P Br_2/KOH Q [(ii) H_2O] (i) NaNO_2 + HCl R

NEET 2026 Solution View → 108

Identify the major product 'Z' in the following sequence of reactions: C_6H_5-CH_2-CH_2-Br [Δ] alc. KOH X HBr Y [Δ] aq. KOH Z

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Consider the chemical reaction scheme shown in the given figure. Which of the following statements is correct regarding the major products Y and Z ?

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Which of the following amines will produce an intensely foul-smelling substance when heated with chloroform and ethanolic potassium hydroxide, but fails to form a stable diazonium

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The given figure shows the potential energy curves for four hydrogen halide molecules as a function of internuclear distance. Match the curves given in List I with the

NEET 2026 Solution View → 112

For the reaction 2NO(g) + O_2(g) arrow 2NO_2(g) at 400 K , the change in internal energy ( Δ U ) is -70 kJ . What will be the enthalpy change ( Δ H ) for the reaction at the same

NEET 2026 Solution View → 113

The solubility of AgSCN in pure water is x times its solubility in a 0.001 M KSCN solution. The value of x is: (Given : K_ sp of AgSCN = 10^ -12 )

NEET 2026 Solution View → 114

During the elemental analysis of a newly synthesized drug molecule, 0.45 g of the sample was subjected to Liebig's combustion method. The experiment yielded 0.66 g of carbon

NEET 2026 Solution View → 115

The carbon-carbon single bond length in propene ( CH_3-CH=CH_2 ) is observed to be slightly shorter than the standard C-C single bond length in propane ( 154 pm ). Which

NEET 2026 Solution View → 116

Consider the skeletal structures of the four hydrocarbons shown below. Which of these hydrocarbons will be oxidized to the corresponding alcohol upon treatment with potassium

NEET 2026 Solution View → 117

A solution is prepared by dissolving W grams of a non-electrolyte polymer (molar mass = 6000 g mol^ -1 ) in enough water to make 500 mL of solution. This solution is found to be

NEET 2026 Solution View → 118

For the galvanic cell reaction given below: 2Cr(s) + 3Cd^ 2+ (aq) arrow 2Cr^ 3+ (aq) + 3Cd(s) The standard cell potential ( E^ ∘ _ cell ) is 0.34 V . Calculate the standard Gibbs

NEET 2026 Solution View → 119

For a first-order decomposition reaction, the half-life period decreases from 40 minutes at 27^ ∘ C to 20 minutes at 37^ ∘ C . What is the activation energy of this reaction?

NEET 2026 Solution View → 120

The given reaction illustrates the direct iodination of ethylbenzene. Unlike chlorination or bromination, this reaction is reversible due to the formation of a strong reducing

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