JEE Main 2024 — 30 Jan Shift 1 (Previous Year Paper)
JEE Main · 2024 · with answers and explanations
- questions
- 89
- Total marks
- 296
- Duration
- 180 minutes
- Negative marking
- −1
Subjects: Mathematics · Physics · Chemistry
Question 1
Mathematics · 4 marks · −1Let and be two vectors such that , and . If , then the angle between and is equal to:
- A.
- B.
- C.
- D.
Correct answer: D
Explanation: ; , ; .
Question 2
Mathematics · 4 marks · −1If has exactly 3 solutions in the interval , , then the roots of the equation belong to:
- A.
- B.
- C.
- D.
Correct answer: D
Explanation: The equation reduces to ; the third solution lies below , so ; has two negative roots.
Question 3
Mathematics · 4 marks · −1Consider the system of linear equations , , , where, . Which one of the following statements is NOT correct?
- A.The system has infinite number of solutions if and
- B.The system is inconsistent if and
- C.The system is consistent if
- D.The system has unique solution if and
Correct answer: B
Explanation: . For consistency needs , i.e. or 15; so is consistent and statement (2) is false.
Question 4
Mathematics · 4 marks · −1The area (in square units) of the region bounded by the parabola and the line , is:
- A.9
- B.8
- C.6
- D.7
Correct answer: A
Explanation: Intersections at ; area .
Question 5
Mathematics · 4 marks · −1Let M denote the median of the following frequency distribution | Class | 0-4 | 4-8 | 8-12 | 12-16 | 16-20 | | Frequency | 3 | 9 | 10 | 8 | 6 | Then 20 M is equal to:
- A.52
- B.208
- C.104
- D.416
Correct answer: B
Explanation: in class 8–12: .
Question 6
Mathematics · 4 marks · −1A line passing through the point A(9, 0) makes an angle of 30° with the positive direction of x-axis. If this line is rotated about A through an angle of 15° in the clockwise direction, then its equation in the new position is:
- A.
- B.
- C.
- D.
Correct answer: A
Explanation: New inclination 15°, slope : .
Question 7
Mathematics · 4 marks · −1If the domain of the function is , then is equal to:
- A.11
- B.8
- C.12
- D.9
Correct answer: A
Explanation: , , : .
Question 8
Mathematics · 4 marks · −1Let denote the sum of first terms of an arithmetic progression. If and , then is:
- A.390
- B.410
- C.405
- D.395
Correct answer: D
Explanation: , ; .
Question 9
Mathematics · 4 marks · −1Let be a differentiable function such that . If the , then is equal to:
- A.2
- B.16
- C.4
- D.1
Correct answer: A
Explanation: The limit equals .
Question 10
Mathematics · 4 marks · −1Let be a non constant twice differentiable function such that . If a real valued function is defined as , then:
- A.
- B. for at least two in (0, 2)
- C. for exactly one in (0, 1)
- D. for no in (0, 1)
Correct answer: B
Explanation: ; Rolle's theorem gives two zeros of .
Question 11
Mathematics · 4 marks · −1Let be the solution of the differential equation such that . Then is equal to:
- A.1
- B.
- C.2
- D.
Correct answer: C
Explanation: , so ; .
Question 12
Mathematics · 4 marks · −1If , then is equal to:
- A.2
- B.6
- C.0
- D.1
Correct answer: C
Explanation: Row operations give , a constant.
Question 13
Mathematics · 4 marks · −1If the length of the minor axis of an ellipse is equal to half of the distance between the foci, then the eccentricity of the ellipse is:
- A.
- B.
- C.
- D.
Correct answer: D
Explanation: .
Question 14
Mathematics · 4 marks · −1Two integers and are chosen with replacement from the set {0, 1, 2, 3,..., 10}. Then the probability that , is:
- A.
- B.
- C.
- D.
Correct answer: C
Explanation: Ordered pairs with difference 6–10: .
Question 15
Mathematics · 4 marks · −1Let and be opposite vertices of a parallelogram . If the diagonal , then the area of the parallelogram is equal to:
- A.
- B.
- C.
- D.
Correct answer: D
Explanation: .
Question 16
Mathematics · 4 marks · −1If , , satisfies the equation , then is equal to:
- A.
- B.1
- C.9
- D.4
Correct answer: B
Explanation: , so .
Question 17
Mathematics · 4 marks · −1Let be the foot of perpendicular from the point (1, 2, 3) on the line . Then is equal to:
- A.102
- B.101
- C.100
- D.99
Correct answer: B
Explanation: ; .
Question 18
Mathematics · 4 marks · −1If the circles and intersect at exactly two distinct points, then:
- A.
- B.
- C.
- D.
Correct answer: D
Explanation: Centres 5 apart, second radius 2: .
Question 19
Mathematics · 4 marks · −1The maximum area of a triangle whose one vertex is at (0, 0) and the other two vertices lie on the curve at points and , where , is:
- A.92
- B.122
- C.88
- D.108
Correct answer: D
Explanation: Area , maximum at : 108.
Question 20
Mathematics · 4 marks · −1The value of is:
- A.
- B.
- C.
- D.
Correct answer: D
Explanation: .
Question 21
Mathematics · 4 marks · −1Let the latus rectum of the hyperbola subtend an angle of at the centre of the hyperbola. If is equal to , where and are co-prime numbers, then is equal to ______.
Correct answer: 182
Question 22
Mathematics · 4 marks · −1If is the shortest distance between the lines , and is the shortest distance between the lines , , then the value of is:
Correct answer: 16
Question 23
Mathematics · 4 marks · −1A group of 40 students appeared in an examination of 3 subjects – Mathematic, Physics and Chemistry. It was found that all students passed in at least one of the subjects, 20 students passed in Mathematics, 25 students passed in Physics, 16 students passed in Chemistry, at most 11 students passed in both Mathematics and Physics, at most 15 students passed in both Physics and Chemistry, at most 15 students passed in both Mathematics and Chemistry. The maximum number of students passed in all the three subjects is ______.
Correct answer: 10
Question 24
Mathematics · 4 marks · −1If the function is differentiable on , then is equal to ______.
Correct answer: 15
Explanation: At : and ; , ; .
Question 25
Mathematics · 4 marks · −1Let be the solution of the differential equation , , . If , and are co-prime numbers, then is equal to ______.
Correct answer: 97
Question 26
Mathematics · 4 marks · −1Let be roots of the equation , where . If assumes the minimum possible value, then is equal to:
Correct answer: 60
Question 27
Mathematics · 4 marks · −1Let upto 10 terms and . If , then is equal to ______.
Correct answer: 353
Question 28
Mathematics · 4 marks · −1Number of integral terms in the expansion of is equal to ______.
Correct answer: 138
Explanation: integral when is a multiple of 6 and is even: → 138 terms.
Question 29
Mathematics · 4 marks · −1The value of , where denotes the greatest integer less than or equal to , is
Correct answer: 155
Question 30
Mathematics · 4 marks · −1Let and let denote the power set of . If the number of functions such that is , and and is least, then is equal to ______.
Correct answer: 44
Explanation: Each is any subset containing : choices, so ; .
Question 31
Physics · 4 marks · −1The diffraction pattern of a light of wavelength 400 nm diffracting from a slit of width 0.2 mm is focused on the focal plane of a convex lens of focal length 100 cm. The width of the 1st secondary maxima will be:
- A.0.02 mm
- B.2 mm
- C.0.2 mm
- D.2 cm
Correct answer: B
Explanation: Width mm.
Question 32
Physics · 4 marks · −1The electric field of an electromagnetic wave in free space is represented as . The corresponding magnetic induction vector will be:
- A.
- B.
- C.
- D.
Correct answer: B
Question 33
Physics · 4 marks · −1A particle is placed at the point A of a frictionless track ABC as shown in figure. It is gently pushed towards right. The speed of the particle when it reaches the point B is: (Take m/s²).

- A. m/s
- B. m/s
- C.10 m/s
- D.20 m/s
Correct answer: A
Explanation: Drop of 0.5 m: m/s.
Question 34
Physics · 4 marks · −1A series L.R circuit connected with an ac source V has a power factor of . If the source of emf is changed to V, the new power factor of the circuit will be:
- A.
- B.
- C.
- D.
Correct answer: C
Explanation: at 1000 rad/s, at 2000 rad/s: .
Question 35
Physics · 4 marks · −1A Zener diode of breakdown voltage 10 V is used as a voltage regulator as shown in the figure. The current through the Zener diode is:

- A.30 mA
- B.0
- C.20 mA
- D.50 mA
Correct answer: A
Explanation: Series current mA, load mA, Zener 30 mA.
Question 36
Physics · 4 marks · −1The electrostatic potential due to an electric dipole at a distance 'r' varies as:
- A.
- B.
- C.
- D.
Correct answer: D
Question 37
Physics · 4 marks · −1Young's modules of material of a wire of length 'L' and cross-sectional area A is Y. If the length of the wire is doubled and cross-sectional area is halved then Young's modules will be:
- A.
- B.
- C.
- D.
Correct answer: A
Explanation: Young's modulus is a material property.
Question 38
Physics · 4 marks · −1All surfaces shown in figure are assumed to be frictionless and the pulleys and the string are light. The acceleration of the block of mass 2 kg is:

- A.
- B.
- C.
- D.
Correct answer: A
Explanation: With for the block, the 4 kg mass moves : , ⇒ .
Question 39
Physics · 4 marks · −1A particle of mass is projected with a velocity '' making an angle of 30° with the horizontal. The magnitude of angular momentum of the projectile about the point of projection when the particle is at its maximum height is:
- A.
- B.
- C.
- D.zero
Correct answer: A
Explanation: with .
Question 40
Physics · 4 marks · −1At which temperature the r.m.s velocity of a hydrogen molecule equal to that of an oxygen molecule at 47°C?
- A.−73 K
- B.20 K
- C.80 K
- D.4 K
Correct answer: B
Explanation: equal: K.
Question 41
Physics · 4 marks · −1Match List-I with List-II. List-I: (A) Coefficient of viscosity; (B) Surface tension; (C) Angular momentum; (D) Rotational kinetic energy List-II: (I) ; (II) ; (III) ; (IV) Chose the correct answer from the options given below:
- A.(A)-(III), (B)-(IV), (C)-(II), (D)-(I)
- B.(A)-(I), (B)-(II), (C)-(III), (D)-(IV)
- C.(A)-(II), (B)-(I), (C)-(IV), (D)-(III)
- D.(A)-(IV), (B)-(III), (C)-(II), (D)-(I)
Correct answer: A
Question 42
Physics · 4 marks · −1A potential divider circuit is shown in figure. The output voltage is:

- A.12 mV
- B.0.5 V
- C.4 V
- D.2 mV
Correct answer: B
Explanation: mA; V.
Question 43
Physics · 4 marks · −1Primary coil of a transformer is connected to 220 V ac. Primary and secondary turns of the transforms are 100 and 10 respectively. Secondary coil of transformer is connected to two series resistances shown in figure. The output voltage is:

- A.15 V
- B.44 V
- C.22 V
- D.7 V
Correct answer: D
Explanation: V; V.
Question 44
Physics · 4 marks · −1Two insulated circular loop A and B of radius 'a' carrying a current of 'I' in the anti clockwise direction as shown in the figure. The magnitude of the magnetic induction at the centre will be:

- A.
- B.
- C.
- D.
Correct answer: B
Explanation: Perpendicular fields each: .
Question 45
Physics · 4 marks · −1The work function of a substance is 3.0 eV. The longest wavelength of light that can cause the emission of photoelectrons from this substance is approximately.
- A.400 nm
- B.200 nm
- C.414 nm
- D.215 nm
Correct answer: C
Explanation: nm.
Question 46
Physics · 4 marks · −1The gravitational potential at a point above the surface of earth is J/kg and the acceleration due to gravity at that point is 6.4 m/s². Assume that the mean radius of earth to be 6400 km. The height of this point above the earth's surface is:
- A.1200 km
- B.1600 km
- C.1000 km
- D.540 km
Correct answer: B
Explanation: km; km.
Question 47
Physics · 4 marks · −1An electric toaster has resistance of 60 Ω at room temperature (27 °C). The toaster is connected to a 220 V supply. If the current flowing through it reaches 2.75 A, the temperature attained by toaster is around: (if /°C)
- A.1694°C
- B.1667°C
- C.694°C
- D.1235°C
Correct answer: A
Explanation: ; C.
Question 48
Physics · 4 marks · −1A spherical body of mass 100 g is dropped from a height of 10 m from the ground. After hitting the ground, the body rebounds to a height of 5 m. The impulse of force impaired by the ground to the body is given by : (given, m/s²)
- A.43.2 kg m s
- B.2.39 kg m s
- C.23.9 kg m s
- D.4.32 kg m s
Correct answer: B
Explanation: .
Question 49
Physics · 4 marks · −1The ratio of the magnitude of the kinetic energy to the potential energy of an electron in the 5th excited state of a hydrogen atom is:
- A.4
- B.
- C.
- D.1
Correct answer: C
Explanation: in any Bohr orbit.
Question 50
Physics · 4 marks · −1A capacitor of capacitance C and potential V has energy E. It is connected to another capacitor of capacitance 2C and potential 2V. Then the loss of energy is , where is ______.
Correct answer: 2
Explanation: Loss .
Question 51
Physics · 4 marks · −1The displacement and the increase in the velocity of a moving particle in the time interval of to s are 125 m and 50 m/s, respectively. The distance travelled by the particle in s is ______ m.
Correct answer: 175
Explanation: ; average velocity in the interval 125, so the next second's displacement is m.
Question 52
Physics · 4 marks · −1A electron of hydrogen atom on an excited state is having energy eV. The maximum number of allowed transitions to lower energy level is ______.
Correct answer: 6
Explanation: : .
Question 53
Physics · 4 marks · −1Consider a Disc of mass 5 kg, radius 2 m, rotating with angular velocity of 10 rad/s about an axis perpendicular to the plane of rotation. An identical disc is kept gently over the rotating disc along the same axis. The energy dissipated so that both the discs continue to rotate together without slipping is ______ J.

Correct answer: 250
Explanation: ; initial KE 500 J; final J; loss 250 J.
Question 54
Physics · 4 marks · −1In a closed organ pipe, the frequence of fundamental note is 30 Hz. A certain amount of water is now poured in the organ pipe so that the fundamental frequency is increased to 110 Hz. If the organ pipe has a cross-sectional area of 2 cm², the amount of water poured in the organ tube is ______ g. (Take speed of sound in air is 330 m/s)
Correct answer: 400
Explanation: Lengths m and m; 2 m of water × 2 cm² = 400 cm³ = 400 g.
Question 55
Physics · 4 marks · −1A ceiling fan having 3 blades of length 80 cm each is rotating with an angular velocity of 1200 rpm. The magnetic field of earth in that region is 0.5 G and angle of dip is 30°. The emf induced across the blades is V. The value of N is ______.
Correct answer: 32
Explanation: ; V.
Question 56
Physics · 4 marks · −1Two cells are connected in opposition as shown. Cell is of 8 V emf and 2 Ω internal resistance; the cell is of 2 V emf and 4 Ω internal resistance. The terminal potential difference of cell is ______ V.

Correct answer: 6
Explanation: A, forced through against its emf: V.
Question 57
Physics · 4 marks · −1The distance between object and its two times magnified real image as produced by a convex lens is 45 cm. The focal length of the lens used is ______ cm.
Correct answer: 10
Explanation: , ; , cm.
Question 58
Physics · 4 marks · −1Each of three blocks P, Q and R shown in figure has a mass of 3 kg. Each of the wires A and B has cross-sectional area 0.005 cm² and Young's modulus N m. Neglecting friction, the longitudinal strain on wire B is ______ . (Take m/s²)

Correct answer: 2
Explanation: ; tension in B N; strain .
Question 59
Physics · 4 marks · −1The horizontal component of earth's magnetic field at a place is T. A very long straight conductor carrying current of A in the direction from South-East to North-West is placed. The force per unit length experienced by the conductor is ______ N/m.
Correct answer: 35
Explanation: Angle 45° with the horizontal field: N/m.
Question 60
Chemistry · 4 marks · −1Example of vinylic halide is:

- A.(Halomethylidene)cyclohexane — X on an exocyclic =CH– carbon
- B.1-(Halomethyl)cyclohexene — CHX on a ring C=C carbon
- C.Halobenzene-type: X on a benzene ring
- D.3-Halocyclohexene — X on the sp carbon next to C=C
Correct answer: A
Question 61
Chemistry · 4 marks · −1This reduction reaction is known as:
- A.Rosenmund reduction
- B.Etard reduction
- C.Wolff-Kishner reduction
- D.Stephen reduction
Correct answer: A
Question 62
Chemistry · 4 marks · −1Choose the correct statements from the following: (A) Ethane-1, 2-diamine is a chelating ligand. (B) Metallic aluminium is produced by electrolysis of aluminium oxide in presence of cryolite. (C) Cyanide ion is used as ligand for leaching of silver. (D) Phosphine act as a ligand in Wilkinson catalyst. (E) The stability constants of and are similar with EDTA complexes. Choose the correct answer from the options given below:
- A.(B), (C), (E) only
- B.(A), (B), (C) only
- C.(C), (D), (E) only
- D.(A), (D), (E) only
Correct answer: B
Question 63
Chemistry · 4 marks · −1The final product A, formed in the following multistep reaction sequence is: Bromobenzene A
- A.Benzamide
- B.Benzoyl bromide
- C.Aniline
- D.Benzoic acid
Correct answer: C
Explanation: PhMgBr → PhCOOH → PhCONH → Hofmann bromamide → PhNH.
Question 64
Chemistry · 4 marks · −1Given below are two statements: Statement (I): The gas liberated on warming a salt with dil , turns a piece of paper dipped in lead acetate into black, it is a confirmatory test for sulphide ion. Statement (II): In statement-I the colour of paper turns black because of formation of lead sulphite. In the light of the above statements, choose the most appropriate answer from the options given below:
- A.Statement I is false but Statement II is true
- B.Statement I is true but Statement II is false
- C.Both Statement I and Statement II are true
- D.Both Statement I and Statement II are false
Correct answer: B
Explanation: The black product is PbS (sulphide), not sulphite.
Question 65
Chemistry · 4 marks · −1Match List-I with List-II. List-I (Species): (A) ; (B) ; (C) ; (D) List-II (Electronic distribution): (I) ; (II) ; (III) ; (IV) Choose the correct answer from the options given below:
- A.(A)-(IV), (B)-(III), (C)-(I), (D)-(II)
- B.(A)-(I), (B)-(II), (C)-(III), (D)-(IV)
- C.(A)-(III), (B)-(IV), (C)-(I), (D)-(II)
- D.(A)-(II), (B)-(I), (C)-(IV), (D)-(III)
Correct answer: C
Question 66
Chemistry · 4 marks · −1Match List-I with List-II. List-I (Molecule): (A) ; (B) ; (C) ; (D) List-II (Shape): (I) T-shape; (II) See saw; (III) Bent; (IV) Square pyramidal Choose the correct answer from the options given below:
- A.(A)-(II), (B)-(I), (C)-(III), (D)-(IV)
- B.(A)-(IV), (B)-(III), (C)-(I), (D)-(II)
- C.(A)-(I), (B)-(II), (C)-(IV), (D)-(III)
- D.(A)-(III), (B)-(IV), (C)-(I), (D)-(II)
Correct answer: B
Question 67
Chemistry · 4 marks · −1Structure of 4-Methylpent-2-enal is:
- A.
- B.
- C.
- D.
Correct answer: B
Question 68
Chemistry · 4 marks · −1Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): There is a considerable increase in covalent radius from N to P. However from As to Bi only a small increase in covalent radius is observed. Reason (R): Covalent and ionic radii in a particular oxidation state increases down the group. In the light of the above statements, choose the most appropriate answer from the options given below:
- A.Both (A) and (R) are true but (R) is not the correct explanation of (A)
- B.(A) is false but (R) is true
- C.Both (A) and (R) are true and (R) is the correct explanation of (A)
- D.(A) is true but (R) is false
Correct answer: A
Explanation: The small increase from As to Bi is due to poorly shielding d and f electrons, which R does not address.
Question 69
Chemistry · 4 marks · −1Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): is an example of allyl halide. Reason (R): Allyl halides are the compounds in which the halogen atom is attached to hybridized carbon atom. In the light of the above statements, choose the most appropriate answer from the options given below:
- A.Both (A) and (R) are true but (R) is not the correct explanation of (A)
- B.(A) is false but (R) is true
- C.Both (A) and (R) are true and (R) is the correct explanation of (A)
- D.(A) is true but (R) is false
Correct answer: D
Explanation: In allyl halides the halogen is on an sp carbon next to C=C.
Question 70
Chemistry · 4 marks · −1Diamagnetic Lanthanoid ions are:
- A. &
- B. &
- C. &
- D. &
Correct answer: A
Explanation: Both are .
Question 71
Chemistry · 4 marks · −1Following is a confirmatory test for aromatic primary amines. Identify reagent (A) and (B). Aniline benzenediazonium chloride Scarlet red dye

- A.A = + HCl, 0–5°C; B = 1-naphthol (α-naphthol)
- B.A = + HCl, 0–5°C; B = aniline
- C.A = + HCl, 0–5°C; B = 2-naphthol (β-naphthol)
- D.A = ; B = phenol
Correct answer: C
Question 72
Chemistry · 4 marks · −1Which of the following molecule/species is most stable?

- A.Cyclopropenyl carbene/anion species (lone pair on the sp carbon of cyclopropene)
- B.1,3-Cyclohexadiene
- C.Cyclopropenyl cation
- D.Cyclopentadienyl cation
Correct answer: C
Explanation: The cyclopropenyl cation is aromatic (2π electrons).
Question 73
Chemistry · 4 marks · −1Compound A formed in the following reaction reacts with B gives the product C. Find out A and B.
- A.A = , B =
- B.A = , B =
- C.A = , B =
- D.A = , B =
Correct answer: C
Question 74
Chemistry · 4 marks · −1Given below are two statements: Statement (I): The orbitals having same energy are called as degenerate orbitals. Statement (II): In hydrogen atom, 3p and 3d orbitals are not degenerate orbitals. In the light of the above statements, choose the most appropriate answer from the options given below:
- A.Statement I is true but Statement II is false
- B.Statement I is false but Statement II is true
- C.Both Statement I and Statement II are true
- D.Both Statement I and Statement II are false
Correct answer: A
Explanation: In hydrogen, energy depends only on .
Question 75
Chemistry · 4 marks · −1What happens to freezing point of benzene when small quantity of naphthalene is added to benzene?
- A.First decreases and then increases
- B.Decreases
- C.Remains unchanged
- D.Increases
Correct answer: B
Question 76
Chemistry · 4 marks · −1Aluminium chloride in acidified aqueous solution forms an ion having geometry.
- A.Trigonal bipyramidal
- B.Tetrahedral
- C.Square planar
- D.Octahedral
Correct answer: D
Explanation: .
Question 77
Chemistry · 4 marks · −1The Lassiagne's extract is boiled with dil before testing for halogens because,
- A. is soluble in .
- B.Silver halides are soluble in .
- C. and NaCN are decomposed by .
- D.AgCN is soluble in .
Correct answer: C
Question 78
Chemistry · 4 marks · −1In the given reactions, identify the reagent A and reagent B. Toluene [Intermediate] Benzaldehyde; Toluene [Intermediate] Benzaldehyde
- A.A – , B –
- B.A – , B –
- C.A – , B –
- D.A – , B –
Correct answer: D
Explanation: Chromic oxide in acetic anhydride gives the benzylidene diacetate; Etard reagent (CrOCl in CS) gives the chromium complex.
Question 79
Chemistry · 4 marks · −1Sugar which does not given reddish brown precipitate with Fehling's reagent, is:
- A.Maltose
- B.Sucrose
- C.Glucose
- D.Lactose
Correct answer: B
Question 80
Chemistry · 4 marks · −1The total number of molecular orbitals formed from 2s and 2p atomic orbitals of a diatomic molecule is ______.
Correct answer: 8
Explanation: 2 × (1 + 3) = 8.
Question 81
Chemistry · 4 marks · −1The pH at which begins to precipitate from a solution containing 0.10 M ions is ______.
Correct answer: 9
Explanation: ; pH 9.
Question 82
Chemistry · 4 marks · −1If the above equation is balanced with integer coefficients, the value of is ______.
Correct answer: 8
Explanation: .
Question 83
Chemistry · 4 marks · −1An ideal gas undergoes a cyclic transformation starting from the point A and coming back to the same point by tracing the path A → B → C → A as shown in the diagram above. The total work done in the process is ______ J.

Correct answer: 200
Explanation: Triangle area J.
Question 84
Chemistry · 4 marks · −1The compound formed by the reaction of ethanal with semi carbazide contains ______ number of nitrogen atoms.
Correct answer: 3
Explanation: has 3 N.
Question 85
Chemistry · 4 marks · −1On a thin layer chromatographic place, an organic compound moved by 3.5 cm, while the solvent moved by 5 cm. The retardation factor of the organic compound is ______ .
Correct answer: 7
Explanation: .
Question 86
Chemistry · 4 marks · −1If IUPAC name of an element is "Unununnium" then the element belongs to nth group of Periodic table. The value of n is ______.
Correct answer: 11
Explanation: Z = 111 (roentgenium), group 11.
Question 87
Chemistry · 4 marks · −1The rate of first order reaction is 0.04 mol L s at 10 minutes and 0.03 mol L s at 20 minutes after initiation. Half life or the reaction is ______ minutes. (Given log 2 = 0.3010, log 3 = 0.4771)
Correct answer: 24
Explanation: ; min.
Question 88
Chemistry · 4 marks · −10.05 cm thick coating of silver is deposited on a plate of 0.05 m² area. The number of silver atoms deposited on plate are ______ . (At mass Ag = 108, d = 7.9 g cm)
Correct answer: 11
Explanation: Volume 25 cm, mass 197.5 g, 1.83 mol → atoms.
Question 89
Chemistry · 4 marks · −1The mass of sodium acetate () required to prepare 250 mL of 0.35 M aqueous solution is ______ g. (Molar mass of is 82.02 g mol)
Correct answer: 7
Explanation: g.