JEE Main Chemistry Important & Repeated Questions 2027

CaCO₃(s) + 2HCl(aq) -> CaCl₂(aq) + CO₂(g) + H₂O(l) Consider the above reaction, what mass of CaCl₂ will be formed if 250 mL of 0.76 M HCl reacts with 1000 g of CaCO₃ ? (Given : Molar mass of Ca, C, O, H and Cl are 40, 12, 16, 1 and 35.5 g mol^-1, respectively) (1) 5.272 g (2) 2.636 g (3) 3.908 g (4) 10.545 g

0.1 mol of the given antiviral compound (P) will weigh ______ *10^-1 g (nearest integer). Compound P is an iodinated, fluorinated pyrimidine nucleoside (a uracil base bearing an iodine, N-linked to a deoxyribose-type sugar ring carrying two OH groups and a ring F substituent) as shown. (Given : molar mass in g mol^-1 H : 1, C : 12, N : 14, O : 16, F : 19, I : 127)

Combustion of glucose (C₆H₁₂O₆) produces CO₂ and water. The amount of oxygen (in g) required for the complete combustion of 900 g of glucose is: [Molar mass of glucose in g mol^-1 = 180] (1) 32 (2) 800 (3) 960 (4) 480

Among 10^-9 g (each) of the following elements, which one will have the highest number of atoms? Element: Pb, Po, Pr and Pt Options: (1) Pb (2) Po (3) Pr (4) Pt

SO₂Cl₂ on reaction with excess of water results into acidic mixture SO₂Cl₂ + 2H₂O -> H₂SO₄ + 2HCl. 16 moles of NaOH is required for the complete neutralisation of the resultant acidic mixture. The number of moles of SO₂Cl₂ used is : (A) 16 (B) 8 (C) 4 (D) 2

Wavenumber for a radiation having 5800 Å wavelength is x × 10 cm^-1. The value of x is _______. (Integer answer)

Which of the following postulate of Bohr's model of hydrogen atom is not in agreement with quantum mechanical model of an atom? Options: (1) An atom can take only certain distinct energies E₁, E₂, E₃, etc. These allowed states of constant energy are called the stationary states of atom. (2) An atom in a stationary state does not emit electromagnetic radiation as long as it stays in the same state. (3) When an electron makes a transition from a higher energy stationary state to a lower energy stationary state, then it emits a photon of light. (4) The electron in a H atom's stationary state moves in a circle around the nucleus.

Frequency of the de-Broglie wave of electron in Bohr's first orbit of hydrogen atom is ________ x 10¹³ Hz (nearest integer). [Given: R_H (Rydberg constant) = 2.18 x 10^-18 J, h (Planck's constant) = 6.6 x 10^-34 J.s.]

The correct set of four quantum numbers for the valence electron of rubidium atom (Z = 37) is : (A) 5, 0, 0, +1/2 (B) 5, 1, 0, +1/2 (C) 5, 1, 1, +1/2 (D) 5, 0, 1, +1/2

If wavelength of the first line of the Paschen series of hydrogen atom is 720 nm, then the wavelength of the second line of this series is ______ nm. (Nearest integer)

Among SO₂, NF₃, NH₃, XeF₂, ClF₃ and SF₄, the hybridization of the molecule with non-zero dipole moment and highest number of lone-pairs of electrons on the central atom is : (1) dsp² (2) sp³d (3) sp³d² (4) sp³

Match the LIST-I with LIST-II LIST-I (Molecule / ion): A. ICl₂^-; B. H₂O; C. SO₂; D. XeF₄ LIST-II (Bond pair : lone pair on the central atom): I. 4 : 2; II. 4 : 1; III. 2 : 3; IV. 2 : 2 Choose the correct answer from the options given below: (1) A-III, B-IV, C-I, D-II (2) A-IV, B-III, C-II, D-I (3) A-III, B-IV, C-II, D-I (4) A-II, B-I, C-IV, D-III

Number of compounds with one lone pair of electrons on central atom amongst following is ______ . O₃, H₂O, SF₄, ClF₃, NH₃, BrF₅, XeF₄

Number of molecules having bond order 2 from the following molecules is _______. C₂, O₂, Be₂, Li₂, Ne₂, N₂, He₂

A molecule with the formula AX₄Y has all it's elements from p-block. Element A is rarest, monoatomic, non-radioactive from its group and has the lowest ionization enthalpy value among A, X and Y. Elements X and Y have first and second highest electronegativity values respectively among all the known elements. The shape of the molecule is : (1) Octahedral (2) Trigonal bipyramidal (3) Square pyramidal (4) Pentagonal planar

Number of molecules from the following which can exhibit hydrogen bonding is ________. (nearest integer) CH₃OH, H₂O, C₂H₆, C₆H₆, ortho-nitrophenol (benzene ring bearing -NO₂ and -OH in ortho positions), HF, NH₃

When ψ_A and ψ_B are the wave functions of atomic orbitals, then σ* is represented by: (1) ψ_A + ψ_B (2) ψ_A - ψ_B (3) ψ_A + 2ψ_B (4) ψ_A - 2ψ_B

The pair from the following pairs having both compounds with net non-zero dipole moment is (1) CH₂Cl₂, CHCl₃ (2) 1,4-Dichlorobenzene, 1,3-Dichlorobenzene (3) cis-butene, trans-butene (4) Benzene, anisidine

Given: DeltaH^o_sub [C (graphite)] = 710 kJ mol^-1 Delta_(C-H) H^o = 414 kJ mol^-1 Delta_(H-H) H^o = 436 kJ mol^-1 Delta_(C=C) H^o = 611 kJ mol^-1 The DeltaH_f^o for CH₂=CH₂ is ______ kJ mol^-1 (nearest integer value)

For the reaction at 298 K, 2A + B -> C. ΔH = 400 kJ mol^-1 and ΔS = 0.2 kJ mol^-1 K^-1. The reaction will become spontaneous above ________ K.

Which of the following is not correct ? (A) ΔG is zero for a reversible reaction (B) ΔG is positive for a spontaneous reaction (C) ΔG is negative for a spontaneous reaction (D) ΔG is positive for a non-spontaneous reaction

(A figure of a cylinder fitted with a piston is provided; the piston can be at position A corresponding to a gas volume of 10 L or at position B corresponding to 90 L.) Consider the figure provided. 1 mol of an ideal gas is kept in a cylinder, fitted with a piston, at the position A, at 18 degree C. If the piston is moved to position B, keeping the temperature unchanged, then 'x' L atm work is done in this reversible process. x = ___ L atm. (nearest integer) [Given: Absolute temperature = degree C + 273.15, R = 0.08206 L atm mol^-1 K^-1]

The density of 'x' M solution ('x' molar) of NaOH is 1.12 g mL^-1, while in molality, the concentration of the solution is 3 m (3 molal). Then x is (Given: Molar mass of NaOH is 40 g/mol) (1) 3.5 (2) 3.8 (3) 3.0 (4) 2.8

When 'x' ×10^-2 mL methanol (molar mass = 32 g; density = 0.792 g/cm³) is added to 100 mL water (density = 1 g/cm³), the following diagram is obtained. [Vapour pressure vs Temperature/K plot for Water, Methanolic solution and Frozen system, with values 270.65 and 273.15 marked on the temperature axis.] x = ________ (nearest integer). [Given : Molal freezing point depression constant of water at 273.15 K is 1.86 K kg mol^-1]

Consider the dissociation of the weak acid HX as given below HX(aq) <=> H^+(aq) + X^-(aq), Ka = 1.2 x 10^-5. [Ka: dissociation constant] The osmotic pressure of 0.03 M aqueous solution of HX at 300 K is ________ x 10^-2 bar (nearest integer). [Given: R = 0.083 L bar mol^-1 K^-1]

2 moles each of ethylene glycol and glucose are dissolved in 500 g of water. The boiling point of the resulting solution is: (Given: Ebullioscopic constant of water = 0.52 K kg mol^-1) Options: (1) 379.2 K (2) 277.3 K (3) 377.3 K (4) 375.3 K

Mass of Urea (NH₂CONH₂) required to be dissolved in 1000 g of water in order to reduce the vapour pressure of water by 25% is ______ g. (Nearest integer) Given: Molar mass of N, C, O and H are 14, 12, 16 and 1 g mol^-1 respectively.

Consider the following equilibrium, CO(g) + 2H₂(g) <=> CH₃OH(g) 0.1 mol of CO along with a catalyst is present in a 2 dm³ flask maintained at 500 K. Hydrogen is introduced into the flask until the pressure is 5 bar and 0.04 mol of CH₃OH is formed. The K_p^theta is ______ *10^-3 (nearest integer). Given : R = 0.08 dm³ bar K^-1 mol^-1 Assume only methanol is formed as the product and the system follows ideal gas behaviour.

An aqueous solution of HCl with pH 1.0 is diluted by adding equal volume of water (ignoring dissociation of water). The pH of HCl solution would (Given log 2 = 0.30) (1) remain same (2) reduce to 0.5 (3) increase to 2 (4) increase to 1.3

In the following system, PCl₅(g) <=> PCl₃(g) + Cl₂(g) at equilibrium, upon addition of xenon gas at constant T & p, the concentration of Options: (1) PCl₃ will increase (2) Cl₂ will decrease (3) PCl₅ will increase (4) PCl₅, PCl₃ & Cl₂ remain constant

For the given hypothetical reactions, the equilibrium constants are as follows: X <=> Y; K₁ = 1.0 Y <=> Z; K₂ = 2.0 Z <=> W; K₃ = 4.0 The equilibrium constant for the reaction X <=> W is (1) 7.0 (2) 8.0 (3) 12.0 (4) 6.0

Consider the following electrochemical cell at standard condition. Au(s) | QH₂, Q | NH₄X (0.01 M) || Ag^+ (1 M) | Ag(s) E_cell = +0.4 V The couple QH₂/Q represents quinhydrone electrode, the half cell reaction is given below : Q + 2e^- + 2H^+ -> QH₂, E°_Q/QH₂ = +0.7 V (Given : E°_Ag+/Ag = +0.8 V and 2.303*R*T/F = 0.06 V) The pK_b value of the ammonium halide salt (NH₄X) used here is ______. (nearest integer)

Given below are two statements: Statement I: Mohr's salt is composed of only three types of ions-ferrous, ammonium and sulfate. Statement II: If the molar conductance at infinite dilution for ferrous, ammonium and sulfate ions are x₁, x₂ and x₃ S cm² mol^-1, respectively then the molar conductance for Mohr's salt solution at infinite dilution would be given by x₁ + x₂ + 2x₃. In the light of the given statements, choose the correct answer from the options given below: (1) Both Statements I and Statement II are true (2) Both Statements I and Statement II are false (3) Statement I is true but Statement II are false (4) Statement I is false but Statement II is true

The standard electrode potential of M^+/M in aqueous solution does not depend on (1) Ionisation of a solid metal atom (2) Sublimation of a solid metal (3) Hydration of a gaseous metal ion (4) Ionisation of a gaseous metal atom

The reaction: (1/2) H₂(g) + AgCl(s) -> H^+(aq) + Cl^-(aq) + Ag(s) occurs in which of the following galvanic cell: (1) Ag | AgCl(s) | KCl(soln.) || AgNO₃(aq.) | Ag (2) Pt | H₂(g) | KCl(soln.) | AgCl(s) | Ag (3) Pt | H₂(g) | HCl(soln.) | AgCl(s) | Ag (4) Pt | H₂(g) | HCl(soln.) | AgNO₃(aq) | Ag

Match List-I with List-II. List-I (Reaction) (A) N₂(g) + O₂(g) -> 2NO(g) (B) 2Pb(NO₃)₂(s) -> 2PbO(s) + 4NO₂(g) + O₂(g) (C) 2Na(s) + 2H₂O(l) -> 2NaOH(aq) + H₂(g) (D) 2NO₂(g) + 2OH^-(aq) -> NO₂^-(aq) + NO₃^-(aq) + H₂O(l) List-II (Type of redox reaction) (I) Decomposition (II) Displacement (III) Disproportionation (IV) Combination Choose the correct answer from the options given below : (1) (A)-(IV), (B)-(I), (C)-(II), (D)-(III) (2) (A)-(II), (B)-(III), (C)-(IV), (D)-(I) (3) (A)-(III), (B)-(II), (C)-(I), (D)-(IV) (4) (A)-(I), (B)-(II), (C)-(III), (D)-(IV)

Chlorine undergoes disproportionation in alkaline medium as shown below : a Cl₂(g) + b OH^-(aq) -> c ClO^-(aq) + d Cl^-(aq) + e H₂O(l) The values of a, b, c and d in a balanced redox reaction are respectively : (A) 2, 4, 1 and 3 (B) 2, 2, 1 and 3 (C) 1, 2, 1 and 1 (D) 3, 4, 4 and 2

Thiosulphate reacts differently with iodine and bromine in the reactions given below: 2S₂O₃^2- + I₂ -> S₄O₆^2- + 2I^- S₂O₃^2- + 5Br₂ + 5H₂O -> 2SO₄^2- + 4Br^- + 10H^+ Which of the following statement justifies the above dual behaviour of thiosulphate? (1) Bromine is a stronger oxidant than iodine (2) Bromine is a weaker oxidant than iodine (3) Thiosulphate undergoes oxidation by bromine and reduction by iodine in these reactions (4) Bromine undergoes oxidation and iodine undergoes reduction in these reactions

In a reaction A + B -> C, initial concentrations of A and B are related as [A]₀ = 8[B]₀. The half lives of A and B are 10 min and 40 min, respectively. If they start to disappear at the same time, both following first order kinetics, after how much time will the concentration of both the reactants be same? Options: (1) 20 min (2) 40 min (3) 60 min (4) 80 min

For a reaction taking place in three steps at same temperature, overall rate constant K = (K₁ K₂)/K₃. If Ea₁, Ea₂ and Ea₃ are 40, 50 and 60 kJ/mol respectively, the overall Ea is ______ kJ/mol.

A person's wound was exposed to some bacteria and then bacterial growth started to happen at the same place. The wound was later treated with some antibacterial medicine and the rate of bacterial decay (r) was found to be proportional with the square of the existing number of bacteria at any instance. Which of the following set of graphs correctly represents the 'before' and 'after' situation of the application of the medicine? [Given: N = No. of bacteria, t = time, bacterial growth follows 1st order kinetics.] (1) Before: N/N₀ rises exponentially with t; After: r decreases with N (2) Before: rises exponentially; After: r increases linearly with N (3) Before: rises exponentially; After: r increases (parabolic) with N (4) Before: rises exponentially; After: r increases (parabolic) with N

For a reaction A -(K₁)-> B -(K₂)-> C. If the rate of formation of B is set to be zero then the concentration of B is given by: (1) (K₁ - K₂)[A] (2) K₁ K₂ [A] (3) (K₁ + K₂)[A] (4) (K₁ / K₂)[A]

Match List - I with List - II List - I : (A) N₂(g) + 3H₂(g) -> 2NH₃(g) ; (B) CO(g) + 3H₂(g) -> CH₄(g) + H₂O(g) ; (C) CO(g) + H₂(g) -> HCHO(g) ; (D) CO(g) + 2H₂(g) -> CH₃OH(g) List - II (catalysts) : (I) Cu ; (II) Cu/ZnO - Cr₂O₃ ; (III) Fe_xO_y + K₂O + Al₂O₃ ; (IV) Ni Choose the correct answer from the options given below : (A) (A)-(II), (B)-(IV), (C)-(I), (D)-(III) (B) (A)-(II), (B)-(I), (C)-(IV), (D)-(III) (C) (A)-(III), (B)-(IV), (C)-(I), (D)-(II) (D) (A)-(III), (B)-(I), (C)-(IV), (D)-(II)

The electron affinity value are negative for A. Be -> Be^- B. N -> N^- C. O -> O^2- D. Na -> Na^- E. Al -> Al^- Choose the most appropriate answer from the options given below: (1) A, B and C only (2) D and E only (3) A and D only (4) A, B, D and E only

Which of the following statements are correct? A. The process of adding an electron to a neutral gaseous atom is always exothermic. B. The process of removing an electron from an isolated gaseous atom is always endothermic. C. The 1st ionization energy of boron is less than that of beryllium. D. The electronegativity of C is 2.5 in CH₄ and CCl₄. E. Li is the most electropositive among elements of group I. Choose the correct answer from the options given below: Options: (1) B, C and E Only (2) B and C Only (3) B and D Only (4) A, C and D Only

Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R : Assertion A : The first ionisation enthalpy decreases across a period. Reason R : The increasing nuclear charge outweighs the shielding across the period. In the light of the above statements, choose the most appropriate from the options given below : (A) Both A and R are true and R is the correct explanation of A (B) Both A and R are true but R is NOT the correct explanation of A (C) A is true but R is false (D) A is false but R is true

The group 14 elements A and B have the first ionisation enthalpy values of 708 and 715 kJ mol^-1 respectively. The above values are lowest among their group members. The nature of their ions A²⁺ and B⁴⁺ respectively is (1) reducing and oxidising (2) oxidising and reducing (3) both reducing (4) both oxidising

Given below are two statements: Statement I: The N-N single bond is weaker and longer than that of P-P single bond. Statement II: Compounds of group 15 elements in +3 oxidation states readily undergo disproportionation reactions. In the light of the above statements, choose the correct answer from the options given below Options: (1) Both Statement I and Statement II are true (2) Both Statement I and Statement II are false (3) Statement I is true but Statement II is false (4) Statement I is false but Statement II is true

Evaluate the following statements related to group 14 elements for their correctness. (A) Covalent radius decreases down the group from C to Pb in a regular manner. (B) Electronegativity decreases from C to Pb down the group gradually. (C) Maximum covalence of C is 4 whereas other elements can expand their covalence due to presence of d orbitals. (D) Heavier elements do not form pπ-pπ bonds. (E) Carbon can exhibit negative oxidation states. Choose the correct answer from the options given below : (1) (A) and (B) Only (2) (C) and (D) Only (3) (A), (B) and (C) Only (4) (C), (D) and (E) Only

Which of the Phosphorus oxoacid can create silver mirror from AgNO₃ solution? Options: 1) H₄P₂O₅ 2) (HPO₃)_n 3) H₄P₂O₆ 4) H₄P₂O₇

The interhalogen compound formed from the reaction of bromine with excess of fluorine is a : (A) hypohalite (B) halate (C) perhalate (D) halite

The metal ions that have the calculated spin-only magnetic moment value of 4.9 B.M. are: A. Cr²⁺ B. Fe²⁺ C. Fe³⁺ D. Co²⁺ E. Mn³⁺ Choose the correct answer from the options given below: Options: (1) A, B and E Only (2) A, D and E Only (3) B and E Only (4) A, C and E Only

Given below are two statements: Statement (I): Fusion of MnO₂ with KOH and an oxidising agent gives dark green K₂MnO₄. Statement (II): Manganate ion on electrolytic oxidation in alkaline medium gives permanganate ion. In the light of the above statements, choose the correct answer from the options given below: (1) Both Statement I and Statement II are true (2) Both Statement I and Statement II are false (3) Statement I is true but Statement II is false (4) Statement I is false but Statement II is true

Consider the following reactions A + NaCl + H₂SO₄ (little amount) -> CrO₂Cl₂ + Side Products CrO₂Cl₂ (Vapour) + NaOH -> B + NaCl + H₂O B + H^+ -> C + H₂O The number of terminal 'O' present in the compound 'C' is ______.

The number of element from the following that do not belong to lanthanoids is Eu, Cm, Er, Tb, Yb and Lu (1) 5 (2) 1 (3) 3 (4) 4

The number of valence electrons present in the metal among Cr, Co, Fe and Ni which has the lowest enthalpy of atomisation is (1) 8 (2) 9 (3) 6 (4) 10

Which of the following statements are correct? (A) The M³⁺/M²⁺ reduction potential for iron is greater than manganese. (B) The higher oxidation states of first row d-block elements get stabilized by oxide ion. (C) Aqueous solution of Cr²⁺ can liberate hydrogen from dilute acid. (D) Magnetic moment of V²⁺ is observed between 4.4 - 5.2 BM. Choose the correct answer from the options given below: (1) (B), (C) only (2) (A), (B), (D) only (3) (A), (B) only (4) (C), (D) only

Given below are two statements : Statement (I) : In octahedral complexes, when Delta₀ < P high spin complexes are formed. When Delta₀ > P low spin complexes are formed. Statement (II) : In tetrahedral complexes because of Delta_t < P, low spin complexes are rarely formed. In the light of the above statements, choose the most appropriate answer from the options given below : (1) Both Statement I and Statement II are correct (2) Both Statement I and Statement II are incorrect (3) Statement I is correct but Statement II is incorrect (4) Statement I is incorrect but Statement II is correct

The number of paramagnetic complexes among [FeF₆]^3-, [Fe(CN)₆]^3-, [Mn(CN)₆]^3-, [Co(C₂O₄)₃]^3-, [MnCl₆]^3-, and [CoF₆]^3-, which involved d²sp³ hybridization is ______

The correct order of the complexes [Co(NH₃)₅(H₂O)]³⁺ (A), [Co(NH₃)₆]³⁺ (B), [Co(CN)₆]^3- (C) and [CoCl(NH₃)₅]²⁺ (D) in terms of wavelength of light absorbed is Options: (1) C > B > A > D (2) C > B > D > A (3) D > C > B > A (4) D > A > B > C

An octahedral complex having molecular composition Co.5NH₃.Cl.SO₄ has two isomers A and B. The solution of A gives a white precipitate with AgNO₃ solution and the solution of B gives white precipitate with BaCl₂ solution. The type of isomerism exhibited by the complex is, (1) Linkage isomerism (2) Co-ordinate isomerism (3) Ionisation isomerism (4) Geometrical isomerism

The number of optical isomers exhibited by the iron complex (A) obtained from the following reaction is ______. FeCl₃ + KOH + H₂C₂O₄ -> A

Consider the following reactions NiS + HNO₃ + HCl -> A + NO + S + H₂O A + NH₄OH + H₃C-C(=N-OH)-C(=N-OH)-CH₃ (dimethylglyoxime) -> B + NH₄Cl + H₂O The number of protons that do not involve in hydrogen bonding in the product B is ________.

An octahedral complex with the formula CoCl₃.nNH₃ upon reaction with excess of AgNO₃ solution gives 2 moles of AgCl. Consider the oxidation state of Co in the complex is 'x'. The value of "x + n" is ___. (1) 3 (2) 6 (3) 5 (4) 8

Given below are two statements: Statement I: N(CH₃)₃ and P(CH₃)₃ can act as ligands to form transition metal complexes. Statement II: As N and P are from same group, the nature of bonding of N(CH₃)₃ and P(CH₃)₃ is always same with transition metals. In the light of the above statements, choose the most appropriate answer from the options given below: (1) Both Statement I and Statement II are correct. (2) Both Statement I and Statement II are incorrect. (3) Statement I is correct but Statement II is incorrect. (4) Statement I is incorrect but Statement II is correct.

On complete combustion 1.0 g of an organic compound (X) gave 1.46 g of CO₂ and 0.567 g of H₂O. The empirical formula mass of compound (X) is ______ g. (Given molar mass in g mol^-1 C : 12, H : 1, O : 16) (1) 15 (2) 30 (3) 45 (4) 60

During estimation of nitrogen by Dumas' method of compound X (0.42 g), where X is piperazine (a six-membered ring with two NH groups at 1,4 positions, C₄H₁₀N₂), ______ mL of N₂ gas will be liberated at STP. (nearest integer) (Given molar mass in g mol^-1 C: 12, H: 1, N: 14)

In qualitative test for identification of presence of phosphorous, the compound is heated with an oxidising agent. Which is further treated with nitric acid and ammonium molybdate respectively. The yellow coloured precipitate obtained is: (1) Na₃PO₄.12MoO₃ (2) (NH₄)₃PO₄.12MoO₃ (3) (NH₄)₃PO₄.12(NH₄)₂MoO₄ (4) MoPO₄.21NH₄NO₃

Which of the following statements are correct? A. Glycerol is purified by vacuum distillation because it decomposes at its normal boiling point. B. Aniline can be purified by steam distillation as aniline is miscible in water. C. Ethanol can be separated from ethanol water mixture by azeotropic distillation because it forms azeotrope. D. An organic compound is pure, if mixed M.P. is remained same. Choose the most appropriate answer from the options given below: (1) A, B, C only (2) A, B, D only (3) A, C, D only (4) B, C, D only

The correct statement among the following, for a "chromatography" purification method is : (1) Non-polar compounds are retained at top and polar compounds come down in column chromatography. (2) R_f is an integral value. (3) Organic compounds run faster than solvent in the thin layer chromatographic plate. (4) R_f of a polar compound is smaller than that of a non-polar compound.

Which of the following is the correct IUPAC name of given organic compound (X)? [Structure X: a but-2-ene with CH₃ groups on C2 and C3 and a CH₂Br group, i.e. 1-bromo-2-methylbut-2-ene skeleton] (1) 4-Bromo-3-methylbut-2-ene (2) 1-Bromo-2-methylbut-2-ene (3) 2-Bromo-2-methylbut-2-ene (4) 3-Bromo-3-methylprop-2-ene

The interaction between π bond and lone pair of electrons present on an adjacent atom is responsible for : (A) Electromeric effect (B) Resonance effect (C) Hyperconjugation (D) Inductive effect

Total number of optically active compounds from the following is _______. (Structures shown: 2,3-dihydroxy-2,3-dimethyl compound H-C(CH₃)(OH)-C(H)(OH)-CH₃ (butane-2,3-diol type with methyls), hexane-2,3,4-triol type (CH₃CH_2-CH(OH)-CH(OH)-CH(OH)-CH₂CH₃), CH_3-CH_2-CH_2-CH_2-OH, CH_3-CH_2-CHCl-CH₃ (2-chlorobutane), CH_3-CH_2-CH_2-CH_2-Cl, (CH₃)₂CH-CH_2-CH_2-Cl.)

Consider the following compound (X): H-C(I)≡C(II)-CH₂(III)-CH(IV)(-CH₃)-CH₃, where carbons are labelled I (terminal alkyne CH), II (alkyne C), III (CH₂), IV (CH bearing a CH₃ branch), followed by a terminal CH₃. The most stable and least stable carbon radicals, respectively, produced by homolytic cleavage of corresponding C-H bond are : (1) II, I (2) III, II (3) II, IV (4) I, IV

Identify the correct statements from the following. A. CH_3-CO-CH_2-CH₃ (butan-2-one) and CH_3-CH_2-CH_2-CHO (butanal) are metamers. B. CH_3-CH_2-CH_2-CN (butanenitrile) and CH_3-CH_2-CH_2-NC (propyl isocyanide) are functional isomers. C. CH_3-CH_2-CH_2-CH_2-OH (butan-1-ol) and CH_3-CH_2-CH(OH)-CH₃ (butan-2-ol) are position isomers. D. CH_3-CH_2-CH_2-CH_2-NH₂ (butan-1-amine) and CH_3-CH_2-NH-CH_2-CH₃ (N-ethylethanamine) are homologous. Choose the correct answer from the options given below: Options: (1) A, B & C Only (2) B & C Only (3) C & D Only (4) A & B Only

The shape of carbocation is: (1) tetrahedral (2) trigonal planar (3) diagonal (4) diagonal pyramidal

Given below are two statements: Statement I: Ozonolysis followed by treatment with Zn, H₂O of cis-2-butene gives ethanal. Statement II: The product obtained by ozonolysis followed by treatment with Zn, H₂O of 3,6-dimethyloct-4-ene has no chiral carbon atom. In the light of the above statements, choose the correct answer from the options given below (1) Both Statement I and Statement II are true (2) Both Statement I and Statement II are False (3) Statement I is true but Statement II is false (4) Statement I is false but Statement II are true

Designate whether each of the following compounds is aromatic or not aromatic. The structures shown are: (a) cyclopentadienyl anion, (b) cyclopentadienyl cation, (c) cyclobutadiene dication, (d) cyclobutadiene dianion, (e) cycloheptatrienyl (tropylium) cation, (f) cyclooctatetraene, (g) cyclobutadiene, (h) cyclopropenyl cation. (1) b, e, f, g aromatic and a, c, d, h not aromatic (2) a, c, d, e, h aromatic and b, f, g not aromatic (3) a, b, c, d aromatic and e, f, g, h not aromatic (4) e, g aromatic and a, b, c, d, f, h not aromatic

In the following given reaction, 'A' is [1-cyclobutyl-substituted alkene: a cyclobutane ring bearing C(CH₃)=CH₂] + HBr -> 'A' major product. Options: 1) 1-bromo-2-methylcyclohexane (Br and CH₃ on adjacent carbons of cyclohexane) 2) 1-bromo-1-methylcyclohexane (Br and CH₃ on same carbon of cyclohexane) 3) 1-bromo-2,2-dimethylcyclopentane (Br on one carbon; gem-dimethyl on adjacent carbon of cyclopentane) 4) 1-bromo-1,2-dimethylcyclopentane (two CH₃ and Br on a cyclopentane ring)

Major product B of the following reaction has ___ pi-bond. (Ethylbenzene, C₆H_5-CH₂CH₃) --KMnO₄ - KOH, delta--> (A) --HNO₃ / H₂SO_4--> (B)

Given below are two statements: Statement (I): S_N2 reactions are 'stereospecific', indicating that they result in the formation of only one stereo-isomer as the product. Statement (II): S_N1 reactions generally result in formation of product as racemic mixtures. In the light of the above statements, choose the correct answer from the options given below: (1) Both Statement I and Statement II are true (2) Both Statement I and Statement II are false (3) Statement I is true but Statement II is false (4) Statement I is false but Statement II is true

Which among the following compounds will undergo fastest S_N2 reaction? All options are cyclobutane-based alkyl bromides: (1) 1-bromo-1-methylcyclobutane (Br and a CH₃ on the same ring carbon; tertiary) (2) (2-bromopropan-2-yl)cyclobutane: cyclobutyl-C(CH₃)₂Br (tertiary/neopentyl-type) (3) (bromomethyl)cyclobutane: cyclobutyl-CH₂Br (primary) (4) (1-bromoethyl)cyclobutane: cyclobutyl-CH(CH₃)Br (secondary)

Assertion A: Hydrolysis of an alkyl chloride is a slow reaction but in the presence of NaI, the rate of the hydrolysis increases. Reason R: I^- is a good nucleophile as well as a good leaving group. In the light of the above statements, choose the correct from the options given below: Options: 1) A is true but R is false 2) Both A and R are true and R is the correct explanation of A 3) Both A and R are true but R is NOT the correct explanation of A 4) A is false but R is true

Which of the following compounds is least likely to give effervescence of CO₂ in presence of aq. NaHCO₃? (1) 4-nitrobenzoic acid (p-NO_2-C₆H_4-COOH) (2) anilinium chloride (Ph-NH₃^+ Cl^-) (3) 3-nitrophenol (m-NO_2-C₆H_4-OH) (4) 2,4,6-trinitrophenol (picric acid)

Given below are two statements : Statement (I) : Vanillin (4-hydroxy-3-methoxybenzaldehyde) will react with NaOH and also with Tollen's reagent. Statement (II) : Vanillin will undergo self aldol condensation very easily. In the light of the above statements, choose the most appropriate answer from the options given below : (1) Both Statement I and Statement II are correct (2) Both Statement I and Statement II are incorrect (3) Statement I is correct but Statement II is incorrect (4) Statement I is incorrect but Statement II is correct

In Reimer-Tiemann reaction, phenol is converted into salicylaldehyde through an intermediate. The structure of intermediate is ________. (1) ortho-CHCl₂ substituted phenol (benzene ring bearing -OH and, ortho to it, -CHCl₂) (2) sodium salt: benzene ring bearing -O^- Na^+ and, ortho to it, -CHO (3) sodium salt: benzene ring bearing -O^- Na^+ and, ortho to it, -CH₃ (4) sodium salt: benzene ring bearing -O^- Na^+ and, ortho to it, -CHCl₂

The major products formed : Anisole (C₆H_5-OCH₃) --(HNO₃, H₂SO₄)--> 'A' --(Br₂ (excess)/Fe)--> 'B'. A and B respectively are : (1) A = 2-nitroanisole and B = 4-bromo-2-nitroanisole (2) A = 4-nitroanisole and B = 2-bromo-4-nitroanisole (3) A = 2-nitroanisole and B = 3,5-dibromo-2-nitroanisole (2-methoxy-1-nitro-3,5-dibromobenzene) (4) A = 4-nitroanisole and B = 2,6-dibromo-4-nitroanisole

The major product (P) in the following reaction is : [3-ethoxy-styrene: benzene ring bearing -O-CH₂CH₃ at one position and -CH=CH₂ at meta position] + conc. HBr (excess), Heat -> (P) (A) 1-bromo-3-(2-bromoethyl)benzene (ring -Br and -CH₂CH₂Br) (B) 3-(2-bromoethyl)phenol (ring -OH and -CH₂CH₂Br) (C) 3-(1-bromoethyl)phenol (ring -OH and -CHBr-CH₃) (D) 1-bromo-3-(1-bromoethyl)benzene (ring -Br and -CHBr-CH₃)

Identify the major products A and B respectively in the following set of reactions. Substrate is 1-methylcyclohexan-1-ol: (1-methylcyclohexan-1-ol) --Conc. H₂SO₄, delta--> A (1-methylcyclohexan-1-ol) --CH₃COCl / Pyridine--> B Options: (1) A = methylenecyclohexane (exocyclic =CH₂) and B = 2-acetyl-1-methylcyclohexan-1-ol (ring with CH₃, OH and COCH₃) (2) A = 1-methylcyclohex-1-ene and B = 1-methylcyclohexyl acetate (ring with CH₃ and OCOCH₃) (3) A = 1-methylcyclohex-1-ene and B = 4-acetyl-1-methylcyclohexan-1-ol (ring with CH₃, OH and CH₃CO at para) (4) A = methylenecyclohexane (exocyclic =CH₂) and B = 1-acetyl-1-methylcyclohexane (ring with CH₃ and COCH₃)

Identify the product (P) in the following reaction: (Cyclopentanecarboxylic acid, cyclopentane-COOH) --i) Br₂ / Red P; ii) H₂O--> (P) Options: (1) 1-bromocyclopentane-1-carboxylic acid (Br on the same ring carbon that bears -COOH; -COOH and -Br) (2) Cyclopentanecarbonyl bromide (ring -COBr) (3) 2-bromocyclopentane-1-carboxylic acid (ring -COOH with -Br on the adjacent carbon) (4) 1-bromocyclopentane-1-carbaldehyde (ring -CHO and -Br on same carbon)

From the compounds given below, number of compounds which give positive Fehling's test is ______ . Benzaldehyde, Acetaldehyde, Acetone, Acetophenone, Methanal, 4-nitrobenzaldehyde, cyclohexane carbaldehyde.

Compound (X) undergoes following sequence of reactions to give the Lactone (Y). Compound (X) --(i) HCHO, KOH (ii) KCN(alc) (iii) H₃O^+--> Lactone (Y) [Y is a five-membered gamma-lactone bearing OH, H, H₃C and CH₃ substituents]. Compound (X) is Options: 1) H₂C(CH₃)-CH_2-CHO 2) (CH₃)₂CH-CHO (H-C(CH₃)_2-CHO) 3) HOH₂C-C(CH₃)_2-CHO 4) HO-CH_2-CH_2-CH_2-CH_2-CHO

An organic compound 'A' with empirical formula C₆H₆O gives sooty flame on burning. Its reaction with bromine solution in low polarity solvent results in high yield of B. B is (structures shown as options; see figure). Option 2: 4-bromophenol (para). Option 4: 2-bromophenol (ortho). Options 1 and 3: brominated dihydrofuran-type structures.

Identify [A], [B] and [C], respectively in the following reaction sequence: [A] --NaNO₂, HCl (273-278 K)--> C₆H_5-N₂^+Cl^- (benzenediazonium chloride) --KI--> [B] --2Na / Dry ether--> [C] Options: (1) [A] aniline (C₆H₅NH₂), [B] chlorobenzene (C₆H₅Cl), [C] benzene (C₆H₆) (2) [A] aniline (C₆H₅NH₂), [B] chlorobenzene (C₆H₅Cl), [C] iodobenzene (C₆H₅I) (3) [A] nitrobenzene (C₆H₅NO₂), [B] iodobenzene (C₆H₅I), [C] biphenyl (C₆H_5-C₆H₅) (4) [A] aniline (C₆H₅NH₂), [B] iodobenzene (C₆H₅I), [C] biphenyl (C₆H_5-C₆H₅)

Given below are two statements: Statement (I): All the following compounds react with p-toluenesulfonyl chloride. C₆H₅NH₂, (C₆H₅)₂NH, (C₆H₅)₃N Statement (II): Their products in the above reaction are soluble in aqueous NaOH. In the light of the above statements, choose the correct answer from the options given below: (1) Both Statement I and Statement II are true (2) Both Statement I and Statement II are false (3) Statement I is true but Statement II is false (4) Statement I is false but Statement II is true

Compound P (M.F. C₁₄H₁₃ON) --(HCl, Delta)--> filter to give Residue Q + Filtrate; Filtrate --(NaOH)--> Oily Liquid R. Compound P is neutral, Q gives effervescence with NaHCO₃ while R reacts with Hinsberg's reagent to give solid soluble in NaOH. Compound P is (options are structures) (1) a methyl-substituted benzamide (C(=O)-NH-) (2) a benzophenone-type N-methyl amine (3) 4-methyl-N-phenylbenzamide (H₃C-C₆H_4-C(=O)-NH-C₆H₅) (4) N-methyl-N-phenylbenzamide (C₆H_5-C(=O)-N(CH₃)-C₆H₅)

9.3 g of pure aniline upon diazotisation followed by coupling with phenol gives an orange dye. The mass of orange dye produced (assume 100% yield/conversion) is ________ g. (nearest integer)

Which of the following is the correct structure of L-Fructose? Options: (Fischer projections of fructose stereoisomers; L-fructose has the reference -OH on C5 on the left and the correct configuration at all stereocentres) (1) CH₂OH-CO-(HO-)CH-(HO-)CH-(HO-)CH-CH₂OH type Fischer projection option 1 (2) Fischer projection option 2 (3) Fischer projection option 3 (4) Fischer projection option 4

The incorrect statements regarding enzymes are : (A) Enzymes are biocatalysts. (B) Enzymes are non-specific and can catalyse different kinds of reactions. (C) Most Enzymes are globular proteins. (D) Enzyme - oxidase catalyses the hydrolysis of maltose into glucose. Choose the correct answer from the option given below : (1) (B) and (D) (2) (B), (C) and (D) (3) (A), (B) and (C) (4) (B) and (C)

Type of amino acids obtained by hydrolysis of proteins is : (A) α (B) β (C) γ (D) δ

The one that does not stabilize 2° and 3° structures of proteins is (1) H-bonding (2) van der Waals forces (3) -O-O- linkage (4) -S-S- linkage

Choose the correct tests with respective observations. (A) CuSO₄ (acidified with acetic acid) + K₄[Fe(CN)₆] -> Chocolate brown precipitate. (B) FeCl₃ + K₄[Fe(CN)₆] -> Prussian blue precipitate. (C) ZnCl₂ + K₄[Fe(CN)₆], neutralised with NH₄OH -> White or bluish white precipitate. (D) MgCl₂ + K₄[Fe(CN)₆] -> Blue precipitate. (E) BaCl₂ + K₄[Fe(CN)₆], neutralised with NaOH -> White precipitate. Choose the correct answer from the options given below : (1) A, B and C only (2) B, D and E only (3) C, D and E only (4) A, D and E only

Match List - I with List - II. List - I (Test) — List - II (Identification) (A) Bayer's test (I) Phenol (B) Ceric ammonium nitrate test (II) Aldehyde (C) Phthalein dye test (III) Alcoholic-OH group (D) Schiff's test (IV) Unsaturation Choose the correct answer from the options given below: (1) (A)-(IV), (B)-(III), (C)-(I), (D)-(II) (2) (A)-(IV), (B)-(I), (C)-(II), (D)-(III) (3) (A)-(II), (B)-(III), (C)-(IV), (D)-(I) (4) (A)-(III), (B)-(I), (C)-(IV), (D)-(II)