JEE Main 2025 — 4 Apr Shift 2 (Previous Year Paper)
JEE Main · 2025 · with answers and explanations
- questions
- 75
- Total marks
- 300
- Duration
- 180 minutes
- Negative marking
- −1
Subjects: Mathematics · Physics · Chemistry
Question 1
Mathematics · 4 marks · −1Let the values of p, for which the shortest distance between the lines and is , be a, b, (a < b). Then the length of the latus rectum of the ellipse is :
- A.
- B.
- C.18
- D.9
Correct answer: A
Explanation: ; ⇒ p = 1 or 3; ellipse (major along y): LR .
Question 2
Mathematics · 4 marks · −1The sum of the infinite series is :
- A.
- B.
- C.
- D.
Correct answer: B
Explanation: ; the sum telescopes to .
Question 3
Mathematics · 4 marks · −1Let the matrix satisfy for . Then the sum of all the elements of is :
- A.52
- B.39
- C.44
- D.53
Correct answer: D
Explanation: ; (sum 5): .
Question 4
Mathematics · 4 marks · −1Let for two distinct values of p the lines touch the ellipse E: at the points A and B. Let the line intersect E at the points C and D. Then the area of the quadrilateral ABCD is equal to :
- A.24
- B.36
- C.20
- D.48
Correct answer: A
Explanation: ; A, B = , C, D = . Area = = 24.
Question 5
Mathematics · 4 marks · −1The axis of a parabola is the line and its vertex and focus are in the first quadrant at distances and units from the origin, respectively. If the point (1, k) lies on the parabola, then a possible value of k is :
- A.4
- B.8
- C.3
- D.9
Correct answer: D
Explanation: Vertex (1,1), focus (2,2), directrix : ; with x = 1: ⇒ k = 1 or 9.
Question 6
Mathematics · 4 marks · −1Let A be the point of intersection of the lines and . Let B and C be the points on the lines and respectively such that . Then the square of the area of the triangle ABC is :
- A.63
- B.57
- C.54
- D.60
Correct answer: C
Explanation: , ; area² .
Question 7
Mathematics · 4 marks · −1Let the product of and be , . Let p and q be the maximum and the minimum values of respectively. Then p + q is equal to :
- A.150
- B.140
- C.130
- D.160
Correct answer: C
Question 8
Mathematics · 4 marks · −1Let and , . If , and , then the value of is :
- A.0
- B.1
- C.11
- D.10
Correct answer: C
Question 9
Mathematics · 4 marks · −1Let f be a differentiable function on such that , . Let . Then the number of times the curve meets x-axis is :
- A.0
- B.1
- C.2
- D.3
Correct answer: C
Explanation: ; : meets at 2 points.
Question 10
Mathematics · 4 marks · −1If the sum of the first 20 terms of the series is , where m and n are coprime, then m + n is equal to :
- A.420
- B.421
- C.422
- D.423
Correct answer: B
Explanation: ; sum : 421.
Question 11
Mathematics · 4 marks · −1Let A = {−3, −2, −1, 0, 1, 2, 3} and R be a relation on A defined by xRy if and only if . Let be the number of elements in R. Let m and n be the minimum number of elements required to be added in R to make it reflexive and symmetric relations, respectively. Then is equal to :
- A.18
- B.17
- C.15
- D.16
Correct answer: B
Question 12
Mathematics · 4 marks · −1If , where , then m + n + k is equal to :
- A.19
- B.20
- C.21
- D.18
Correct answer: A
Explanation: : 19.
Question 13
Mathematics · 4 marks · −1Let the mean and the standard deviation of the observation 2, 3, 3, 4, 5, 7, a, b be 4 and respectively. Then the mean deviation about the mode of these observations is :
- A.2
- B.
- C.1
- D.
Correct answer: C
Explanation: a + b = 8 and ⇒ a = b = 4; mode 4; absolute deviations 2,1,1,0,1,3,0,0 sum to 8: MD = 1.
Question 14
Mathematics · 4 marks · −1Let the sum of the focal distances of the point P(4, 3) on the hyperbola H: be . If for H, the length of the latus rectum is and the product of the focal distances of the point P is m, then is equal to :
- A.186
- B.184
- C.185
- D.187
Correct answer: C
Question 15
Mathematics · 4 marks · −1Let a > 0. If the function attains its local maximum and minimum values at the points and respectively such that , then is equal to :
- A.24
- B.15
- C.18
- D.13
Correct answer: C
Explanation: : , a = 3; , : 18.
Question 16
Mathematics · 4 marks · −1A line passing through the point A(−2, 0), touches the parabola P: at the point B in the first quadrant. The area, of the region bounded by the line AB, parabola P and the x-axis, is :
- A.
- B.
- C.3
- D.2
Correct answer: A
Explanation: Tangent from (−2, 0) touches at B(6, 2). Area = triangle under AB from x = −2 to 6 (= 8) minus : .
Question 17
Mathematics · 4 marks · −1Let the domains of the functions and be and , respectively. Then is equal to :
- A.15
- B.13
- C.14
- D.16
Correct answer: A
Question 18
Mathematics · 4 marks · −1Consider two sets A and B, each containing three numbers in A.P. Let the sum and the product of the elements of A be 36 and p respectively and the sum and the product of the elements of B be 36 and q respectively. Let d and D be the common differences of AP\'s in A and B respectively such that D = d + 3, d > 0. If , then p − q is equal to
- A.450
- B.540
- C.630
- D.600
Correct answer: B
Explanation: , ; with D = d + 3 gives d = 6, D = 9; .
Question 19
Mathematics · 4 marks · −1If a curve passes through the point and satisfies the differential equation , , then at x = 2, the value of is :
- A.
- B.
- C.
- D.
Correct answer: A
Question 20
Mathematics · 4 marks · −1The centre of a circle C is at the centre of the ellipse E: , a > b. Let C pass through the foci and of E such that the circle C and the ellipse E intersect at four points. Let P be one of these four points. If the area of the triangle is 30 and the length of the major axis of E is 17, then the distance between the foci of E is :
- A.13
- B.26
- C.12
- D.
Correct answer: A
Explanation: Right angle at P: ; ⇒ 2c = 13.
Question 21
Mathematics · 4 marks · −1Let the three sides of a triangle ABC be given by the vectors , and . Let G be the centroid of the triangle ABC. Then is equal to ______.
Correct answer: 164
Explanation: ; ×6 = 164.
Question 22
Mathematics · 4 marks · −1Let m and n, (m < n), be two 2-digit numbers. Then the total numbers of pairs (m, n), such that gcd (m, n) = 6, is ______.
Correct answer: 64
Question 23
Mathematics · 4 marks · −1If where C is the constant of integration and , then m + n is equal to ______.
Correct answer: 379
Question 24
Mathematics · 4 marks · −1If is a root of the equation and , then n is equal to ______.
Correct answer: 11
Explanation: Terms: 1, 1, 4 repeating (sum 6 per period): n = 11 gives 6·3 + 1 + 1 = 20.
Question 25
Mathematics · 4 marks · −1A card from a pack of 52 cards is lost. From the remaining 51 cards, n cards are drawn and are found to be spades. If the probability of the lost card to be a spade is , then n is equal to ______.
Correct answer: 2
Explanation: ⇒ n = 2.
Question 26
Physics · 4 marks · −1Two polarisers and are placed in such a way that the intensity of the transmitted light will be zero. A third polariser is inserted in between and , at particular angle between and . The transmitted intensity of the light passing the through all three polarisers is maximum. The angle between the polarisers and is :
- A.
- B.
- C.
- D.
Correct answer: C
Question 27
Physics · 4 marks · −1A radioactive material P first decays into Q and then Q decays to non-radioactive material R. Which of the following figure represents time dependent mass of P, Q and R ?

- A.P decays; Q and R both rise monotonically and saturate (Q above R)
- B.P decays; curve labelled R rises then falls; curve labelled Q rises steadily
- C.P decays; Q and R both rise steeply (crossing near the end)
- D.P decays exponentially; Q rises to a maximum then falls; R rises monotonically
Correct answer: D
Question 28
Physics · 4 marks · −1Given below are two statements : Statement (I) : The dimensions of Planck's constant and angular momentum are same. Statement (II) : In Bohr's model electron revolve around the nucleus only in those orbits for which angular momentum is integral multiple of Planck's constant. In the light of the above statements, choose the most appropriate answer from the options given below :
- A.Statement I is correct but Statement II is incorrect
- B.Both Statement I and Statement II are incorrect
- C.Both Statement I and Statement II are correct
- D.Statement I is incorrect but Statement II is correct
Correct answer: A
Explanation: Quantisation is in multiples of , not h.
Question 29
Physics · 4 marks · −1There are 'n' number of identical electric bulbs, each is designed to draw a power p independently from the mains supply. They are now joined in series across the mains supply. The total power drawn by the combination is :
- A.
- B.np
- C.p
- D.
Correct answer: D
Question 30
Physics · 4 marks · −1Consider a n-type semiconductor in which and are number of electrons and holes, respectively. (A) Holes are minority carriers (B) The dopant is a pentavalent atom (C) (where is number of electrons or holes in semiconductor when it is intrinsic form) (D) (E) The holes are not generated due to the donors. Choose the correct answer from the options given below :
- A.(A), (B), (E) only
- B.(A), (C), (D) only
- C.(A), (C), (E) only
- D.(A), (B), (C) only
Correct answer: A
Question 31
Physics · 4 marks · −1Consider a rectangular sheet of solid material of length = 9 cm and width d = 4 cm. The coefficient of linear expansion is at room temperature and one atmospheric pressure. The mass of sheet m = 0.1 kg and the specific heat capacity = 900 J . If the amount of heat supplied to the material is J then change in area of the rectangular sheet is :
- A.
- B.
- C.
- D.
Correct answer: D
Explanation: ΔT = 810/(0.1×900) = 9 K; m².
Question 32
Physics · 4 marks · −1A metallic ring is uniformly charged as shown in figure. AC and BD are two mutually perpendicular diameters. Electric field due to arc AB at 'O' is 'E' in magnitude. What would be the magnitude of electric field at 'O' due to arc ABC ?

- A.E
- B.Zero
- C.E/2
- D.2E
Correct answer: A
Explanation: Arcs AB and BC give fields of magnitude E at 90° to each other: .
Question 33
Physics · 4 marks · −1There are two vessels filled with an ideal gas where volume of one is double the volume of other. The large vessel contains the gas at 8 kPa at 1000 K while the smaller vessel contains the gas at 7 kPa at 500 K. If the vessels are connected to each other by a thin tube allowing the gas to flow and the temperature of both vessels is maintained at 600 K, at steady state the pressure in the vessels will be (in kPa).
- A.6
- B.24
- C.18
- D.4.4
Correct answer: A
Explanation: ⇒ , P = 6 kPa.
Question 34
Physics · 4 marks · −1A cylindrical rod of length 1 m and radius 4 cm is mounted vertically. It is subjected to a shear force of N at the top. Considering infinitesimally small displacement in the upper edge, the angular displacement of the rod axis from its original position would be : (shear moduli, G = N/)
- A.
- B.
- C.
- D.
Correct answer: B
Explanation: .
Question 35
Physics · 4 marks · −1A wheel is rolling on a plane surface. The speed of a particle on the highest point of the rim is 8 m/s. The speed of the particle on the rim of the wheel at the same level as the centre of wheel, will be :
- A. m/s
- B.8 m/s
- C.4 m/s
- D. m/s
Correct answer: D
Explanation: ; side point: .
Question 36
Physics · 4 marks · −1Three parallel plate capacitors , and each of capacitance 5 F are connected as shown in figure. The effective capacitance between points A and B, when the space between the parallel plates of capacitor is filled with a dielectric medium having dielectric constant of 4, is :

- A.30 F
- B.9 F
- C.7.5 F
- D.22.5 F
Correct answer: B
Explanation: : series with 5 gives 4; plus 5 = 9 μF.
Question 37
Physics · 4 marks · −1Displacement of a wave is expressed as m. The wavelength of the wave when its velocity is 300 m/s is : ( = 3.14)
- A.0.5 m
- B.5 m
- C.0.33 m
- D.3 m
Correct answer: D
Explanation: f = 100 Hz, λ = 3 m.
Question 38
Physics · 4 marks · −1A block of mass 25 kg is pulled along a horizontal surface by a force at an angle 45° with the horizontal. The friction coefficient between the block and the surface is 0.25. The block travels at a uniform velocity. The workdone by the applied force during a displacement of 5 m of the block is :
- A.735 J
- B.970 J
- C.245 J
- D.490 J
Correct answer: C
Explanation: ⇒ ; W = 49 × 5 = 245 J.
Question 39
Physics · 4 marks · −1In an electromagnetic system, a quantity defined as the ratio of electric dipole moment and magnetic dipole moment has dimension of . The value of P and Q are :
- A.−1, 0
- B.1, −1
- C.−1, 1
- D.0, −1
Correct answer: D
Explanation: : P = 0, Q = −1.
Question 40
Physics · 4 marks · −1Match List - I with List - II. List - I: (A) Isobaric (B) Isochoric (C) Adiabatic (D) Isothermal. List - II: (I) ΔQ = ΔW (II) ΔQ = ΔU (III) ΔQ = zero (IV) ΔQ = ΔU + PΔV. Choose the correct answer from the options given below :
- A.(A)-(II), (B)-(IV), (C)-(III), (D)-(I)
- B.(A)-(IV), (B)-(II), (C)-(III), (D)-(I)
- C.(A)-(IV), (B)-(I), (C)-(III), (D)-(II)
- D.(A)-(IV), (B)-(III), (C)-(II), (D)-(I)
Correct answer: B
Question 41
Physics · 4 marks · −1The displacement x versus time graph is shown below. (A) The average velocity during 0 to 3 s is 10 m/s (B) The average velocity during 3 to 5 s is 0 m/s (C) The instantaneous velocity at t = 2 s is 5 m/s (D) The average velocity during 5 to 7 s and instantaneous velocity at t = 6.5 s are equal (E) The average velocity from t = 0 to t = 9 s is zero. Choose the correct answer from the options given below :

- A.(A), (D), (E) only
- B.(B), (C), (E) only
- C.(B), (D), (E) only
- D.(B), (C), (D) only
Correct answer: B
Explanation: (B) x is constant from 3 to 5 s; (C) slope of the straight segments through t = 2 s is 5 m/s; (E) x(9) = x(0) = 0. (A) is 5/3 m/s and (D) compares −2.5 m/s with −10 m/s, so both are false.
Question 42
Physics · 4 marks · −1From the combination of resistors with resistances values and , which of the following combination is the best circuit to get an equivalent resistance of 6 ?

- A.All four in parallel
- B., , in series, the combination in parallel with
- C. ∥ , in series with , all in parallel with
- D.( + ) in parallel with ( + )
Correct answer: D
Explanation: (5+5) ∥ (5+10) = 10·15/25 = 6 Ω.
Question 43
Physics · 4 marks · −1A finite size object is placed normal to the principal axis at a distance of 30 cm from a convex mirror of focal length 30 cm. A plane mirror is now placed in such a way that the image produced by both the mirrors coincide with each other. The distance between the two mirrors is :
- A.45 cm
- B.22.5 cm
- C.7.5 cm
- D.15 cm
Correct answer: C
Explanation: Convex-mirror image is 15 cm behind it, i.e. 45 cm from the object. A plane mirror at distance d from the object forms an image 2d from the object: 2d = 45, d = 22.5 cm, so the mirrors are 30 − 22.5 = 7.5 cm apart.
Question 44
Physics · 4 marks · −1For the determination of refractive index of glass slab, a travelling microscope is used whose main scale contains 300 equal divisions equals to 15 cm. The vernier scale attached to the microscope has 25 divisions equals to 24 divisions of main scale. The least count (LC) of the travelling microscope is (in cm) :
- A.0.002
- B.0.001
- C.0.0025
- D.0.0005
Correct answer: A
Explanation: MSD = 0.05 cm; LC = MSD/25 = 0.002 cm.
Question 45
Physics · 4 marks · −1An object is kept at rest at a distance of 3R above the earth\'s surface where R is earth\'s radius. The minimum speed with which it must be projected so that it does not return to earth is : (Assume M = mass of earth, G = Universal gravitational constant)
- A.
- B.
- C.
- D.
Correct answer: C
Explanation: .
Question 46
Physics · 4 marks · −1If an optical medium possesses a relative permeability of and relative permittivity of , then the velocity of light is greater in vacuum than that in this medium by ______ times. ( H/m, F/m, c = m/s)
Correct answer: 6
Explanation: .
Question 47
Physics · 4 marks · −1A solid sphere with uniform density and radius R is rotating initially with constant angular velocity () about its diameter. After some time during the rotation its starts loosing mass at a uniform rate, with no change in its shape. The angular velocity of the sphere when its radius become R/2 is . The value of x is ______.
Correct answer: 32
Explanation: I ∝ R⁵ (uniform density): ω ∝ 1/R⁵ → x = 32.
Question 48
Physics · 4 marks · −1An inductor of self inductance 1 H is connected in series with a resistor of 100 ohm and an ac supply of 100 volt, 50 Hz. Maximum current flowing in the circuit is ______ A.
Correct answer: 1
Explanation: , ; A (taking 100π V as rms).
Question 49
Physics · 4 marks · −1A particle of charge 1.6 C and mass 16 g is present in a strong magnetic field of 6.28 T. The particle is then fired perpendicular to magnetic field. The time required for the particle to return to original location for the first time is ______ s. ( = 3.14)
Correct answer: 0
Explanation: s, which rounds to the integer 0 (NTA key: 0).
Question 50
Physics · 4 marks · −1In a Young's double slit experiment, two slits are located 1.5 mm apart. The distance of screen from slits is 2 m and the wavelength of the source is 400 nm. If the 20 maxima of the double slit pattern are contained within the central maximum of the single slit diffraction pattern, then the width of each slit is cm, where x-value is ______.
Correct answer: 15
Explanation: ⇒ mm = 15 × 10⁻³ cm.
Question 51
Chemistry · 4 marks · −1Consider the following plots of log of rate constant k (log k) vs for three different reactions. The correct order of activation energies of these reactions is :

- A.
- B.
- C.
- D.
Correct answer: D
Explanation: Steeper negative slope = larger Ea: 2 > 1 > 3.
Question 52
Chemistry · 4 marks · −1Consider the ground state of chromium atom (Z = 24). How many electrons are with Azimuthal quantum number and respectively ?
- A.12 and 5
- B.16 and 4
- C.12 and 4
- D.16 and 5
Correct answer: A
Explanation: : p electrons 12, d electrons 5.
Question 53
Chemistry · 4 marks · −1Consider the following molecule (X). [A tricyclic triene: a cyclopentene ring fused to a cyclohexene ring, with a further five-membered ring bearing a trisubstituted C=C at a ring-fusion carbon.] The major product formed when the given molecule (X) is treated with HBr (1 eq) is :

- A.HBr adds to the six-membered-ring C=C (Br on the carbon remote from the fusion)
- B.HBr adds to the five-membered-ring disubstituted C=C (Br on a CH next to the fusion)
- C.HBr adds to the trisubstituted C=C, Br on the tertiary ring-fusion carbon
- D.HBr adds to the five-membered-ring C=C (Br on the CH adjacent to CH2)
Correct answer: C
Explanation: Protonation of the trisubstituted alkene gives the most stable (tertiary) carbocation: Br on the tertiary carbon.
Question 54
Chemistry · 4 marks · −1Given below are two statements : Statement (I) : Alcohols are formed when alkyl chlorides are treated with aqueous potassium hydroxide by elimination reaction. Statement (II) : In alcoholic potassium hydroxide, alkyl chlorides form alkenes by abstracting the hydrogen from the β-carbon. In the light of the above statements, choose the most appropriate answer from the options given below :
- A.Statement I is correct but Statement II is incorrect
- B.Statement I is incorrect but Statement II is correct
- C.Both Statement I and Statement II are incorrect
- D.Both Statement I and Statement II are correct
Correct answer: B
Question 55
Chemistry · 4 marks · −1The IUPAC name of the following compound is :
- A.4-Hydroxyhept-1-en-6-yne
- B.Hept-6-en-1-yn-4-ol
- C.4-Hydroxyhept-6-en-1-yne
- D.Hept-1-en-6-yn-4-ol
Correct answer: D
Question 56
Chemistry · 4 marks · −1The correct order of basicity for the following molecules is : (P) N-methyl-2-piperidone (six-membered lactam); (Q) N-methyl-2-piperidone with a C=C in the ring (N-methyl dihydropyridinone); (R) 2-quinuclidone (bridged bicyclic lactam in which the N lone pair cannot conjugate with C=O).

- A.Q > P > R
- B.R > P > Q
- C.R > Q > P
- D.P > Q > R
Correct answer: C
Explanation: In R the bridgehead N cannot delocalise into C=O (Bredt), so it is most basic. In Q the C=C is conjugated with C=O, which reduces the carbonyl demand on the N lone pair, so Q is more basic than the simple lactam P.
Question 57
Chemistry · 4 marks · −1The elements of Group 13 with highest and lowest first ionisation enthalpies are respectively :
- A.B & In
- B.B & Ga
- C.B & Tl
- D.Tl & B
Correct answer: A
Explanation: IE₁: B 801, Al 577, Ga 579, In 558, Tl 589 kJ/mol.
Question 58
Chemistry · 4 marks · −1Which among the following compounds give yellow solid when reacted with NaOI/NaOH ? (A) (B) (C) (D) (E) . Choose the correct answer from the options given below :
- A.(A) and (C) Only
- B.(C) and (D) Only
- C.(A), (C) and (D) Only
- D.(B), (C) and (E) Only
Correct answer: A
Question 59
Chemistry · 4 marks · −1Match List - I with List - II. List - I (Separation of): (A) Aniline from aniline-water mixture (B) Glycerol from spent-lye in soap industry (C) Different fractions of crude oil in petroleum industry (D) Chloroform-Aniline mixture. List - II (Separation Technique): (I) Simple distillation (II) Fractional distillation (III) Distillation at reduced pressure (IV) Steam distillation. Choose the correct answer from the options given below :
- A.(A)-(II), (B)-(I), (C)-(IV), (D)-(III)
- B.(A)-(I), (B)-(II), (C)-(III), (D)-(IV)
- C.(A)-(IV), (B)-(III), (C)-(II), (D)-(I)
- D.(A)-(III), (B)-(IV), (C)-(I), (D)-(II)
Correct answer: C
Question 60
Chemistry · 4 marks · −1A dipeptide, "x" on complete hydrolysis gives "y" and "z". "y" on treatment with aq. produces lactic acid. On the other hand "z" on heating gives the following cyclic molecule (2,5-diketopiperazine: six-membered ring –CH2–CO–NH–CH2–CO–NH–). Based on the information given, the dipeptide X is :

- A.alanine-glycine
- B.valine-leucine
- C.valine-glycine
- D.alanine-alanine
Correct answer: A
Explanation: y = alanine (gives lactic acid), z = glycine (forms the diketopiperazine).
Question 61
Chemistry · 4 marks · −1A toxic compound "A" when reacted with NaCN in aqueous acidic medium yields an edible cooking component and food preservative "B". "B" is converted to "C" by diborane and can be used as an additive to petrol to reduce emission. "C" upon reaction with oleum at 140°C yields an inhalable anesthetic "D". Identify "A", "B", "C" & "D", respectively :
- A.Acetaldehyde; 2-hydroxypropanoic acid; propanoic acid; dipropyl ether
- B.Ethanol; acetonitrile; ethylamine; ethylene
- C.Methanol; acetic acid; ethanol; diethyl ether
- D.Methanol; formaldehyde; methyl chloride; chloroform
Correct answer: C
Question 62
Chemistry · 4 marks · −1The incorrect relationship in the following pairs in relation to ionisation enthalpies is :
- A.
- B.
- C.
- D.
Correct answer: C
Explanation: Removing an electron from (, half-filled) is harder than from (): IE of > .
Question 63
Chemistry · 4 marks · −1Consider the given data : (a) ΔH = −69.01 kJ (b) ΔH = −72.79 kJ . Choose the correct statement :
- A.The heat of dilution for the HCl (HCl.10 to HCl.40 ) is 3.78 kJ .
- B.The heat of formation of HCl solution is represented by both (a) and (b).
- C.The heat of solution depends on the amount of solvent.
- D.Dissolution of gas in water is an endothermic process.
Correct answer: C
Question 64
Chemistry · 4 marks · −1Given below are two statements : Statement (I) : For , all three possible structures may be drawn as follows. [I: both lone pairs axial (trigonal planar F); II: one lone pair axial, one equatorial; III: both lone pairs equatorial (T-shape)] Statement (II) : Structure III is most stable, as the orbitals having the lone pairs are axial, where the lp−bp repulsion is minimum. In the light of the above statements, choose the most appropriate answer from the options given below :

- A.Both Statement I and Statement II are incorrect
- B.Statement I is correct but Statement II is incorrect
- C.Statement I is incorrect but Statement II is correct
- D.Both Statement I and Statement II are correct
Correct answer: B
Explanation: Structure III (lone pairs equatorial) is most stable, but the reason given (lone pairs axial) is wrong.
Question 65
Chemistry · 4 marks · −1Half life of zero order reaction A → product is 1 hour, when initial concentration of reactant is 2.0 mol . The time required to decrease concentration of A from 0.50 to 0.25 mol is :
- A.60 min
- B.4 hour
- C.0.5 hour
- D.15 min
Correct answer: D
Explanation: k = 1 mol L⁻¹ h⁻¹; Δc = 0.25 → 0.25 h = 15 min.
Question 66
Chemistry · 4 marks · −1'X' is the number of electrons in orbitals of the most stable complex ion among , , and . The nature of oxide of vanadium of the type is :
- A.Neutral
- B.Basic
- C.Acidic
- D.Amphoteric
Correct answer: D
Explanation: NTA key: amphoteric, which corresponds to (X = 5).
Question 67
Chemistry · 4 marks · −1Given below are two statements : Statement (I) : The first ionisation enthalpy of group 14 elements is higher than the corresponding elements of group 13. Statement (II) : Melting points and boiling points of group 13 elements are in general much higher than those of corresponding elements of group 14. In the light of the above statements, choose the most appropriate answer from the options given below :
- A.Both Statement I and Statement II are incorrect
- B.Statement I is correct but Statement II is incorrect
- C.Both Statement I and Statement II are correct
- D.Statement I is incorrect but Statement II is correct
Correct answer: B
Question 68
Chemistry · 4 marks · −1In which pairs, the first ion is more stable than the second ? (A) 1-methoxycyclohexyl... [cyclohexyl cation with +on a CH bearing OMe side chain: ––OMe] & [––Me] (B) [cyclohexyl carbanion bearing an o-nitrophenyl group] & [cyclohexyl cation bearing an o-nitrophenyl group] (C) [cyclohexylmethyl cation, ] & [cyclohex-1-enylmethyl cation (allylic)] (D) [] & [ type: –OMe].

- A.(A) & (B) only
- B.(A) & (C) only
- C.(B) & (C) only
- D.(B) & (D) only
Correct answer: A
Explanation: (A) α-methoxy cation is resonance-stabilised; (B) the carbanion is stabilised by the o-nitroaryl group while the cation is destabilised. (C) the allylic cation is more stable; (D) the methoxy-stabilised cation is more stable.
Question 69
Chemistry · 4 marks · −1Given below are two statements : Statement (I) : Molal depression constant is given by , where symbols have their usual meaning. Statement (II) : for benzene is less than the for water. In the light of the above statements, choose the most appropriate answer from the options given below :
- A.Both Statement I and Statement II are correct
- B.Statement I is incorrect but Statement II is correct
- C.Both Statement I and Statement II are incorrect
- D.Statement I is correct but Statement II is incorrect
Correct answer: D
Explanation: (I correct in form); (benzene) 5.12 > water 1.86 (II incorrect).
Question 70
Chemistry · 4 marks · −1The correct order of , , and complex species based on the number of unpaired electrons present is :
- A.
- B.
- C.
- D.
Correct answer: C
Explanation: 5 > 4 > 0 = 0.
Question 71
Chemistry · 4 marks · −1x mg of (molar mass = 58) is required to be dissolved in 1.0 L of water to produce a pH of 10.0 at 298 K. The value of x is ______ mg. (Nearest integer) (Given : is assumed to dissociate completely in )
Correct answer: 3
Explanation: ⇒ mol × 58 g = 2.9 mg ≈ 3.
Question 72
Chemistry · 4 marks · −1The amount of calcium oxide produced on heating 150 kg limestone (75% pure) is ______ kg. (Nearest integer) Given : Molar mass (in g ) of Ca-40, O-16, C-12
Correct answer: 63
Explanation: 112.5 kg × 56/100 = 63 kg.
Question 73
Chemistry · 4 marks · −1A metal complex with a formula is involved in hybridisation. It upon reaction with excess of solution gives 'x' moles of AgCl. Consider 'x' is equal to the number of lone pairs of electron present in central atom of . Then the number of geometrical isomers exhibited by the complex is ______.
Correct answer: 2
Explanation: has 1 lone pair ⇒ x = 1: , type : fac and mer = 2.
Question 74
Chemistry · 4 marks · −1The molar conductance of an infinitely dilute solution of ammonium chloride was found to be 185 S and the ionic conductance of hydroxyl and chloride ions are 170 and 70 S , respectively. If molar conductance of 0.02 M solution of ammonium hydroxide is 85.5 S , its degree of dissociation is given by . The value of x is ______. (Nearest integer)
Correct answer: 3
Explanation: ; α = 85.5/285 = 0.3.
Question 75
Chemistry · 4 marks · −1Sea water, which can be considered as a 6 molar (6 M) solution of NaCl, has a density of 2 g . The concentration of dissolved oxygen () in sea water is 5.8 ppm. Then the concentration of dissolved oxygen () in sea water, is m. x = ______. (Nearest integer) Given : Molar mass of NaCl is 58.5 g , Molar mass of is 32 g
Correct answer: 2
Explanation: 1 L: 2000 g solution, 351 g NaCl, water 1649 g; = 0.0116 g = 3.625 × 10⁻⁴ mol; molality 2.2 × 10⁻⁴ → 2.