JEE Main 2026 — 28 Jan Shift 1 (9:00 AM - 12:00 PM) (Previous Year
JEE Main · 2026 · with answers and explanations
- questions
- 74
- Total marks
- 296
- Duration
- 180 minutes
- Negative marking
- −1
Subjects: Mathematics · Physics · Chemistry
Question 1
Mathematics · 4 marks · −1Let be a set of polynomials. Then the number of polynomials in S, which are divisible by , is
- A.120
- B.10
- C.20
- D.6
Correct answer: B
Explanation: needs , : .
Question 2
Mathematics · 4 marks · −1If , and , then is equal to:
- A.
- B.
- C.
- D.
Correct answer: D
Question 3
Mathematics · 4 marks · −1If , where , are the roots of the equation such that , then the sum of all possible values of is
- A.8
- B.6
- C.4
- D.2
Correct answer: B
Explanation: Roots 1 and ; the condition gives or : sum 6.
Question 4
Mathematics · 4 marks · −1Let z be a complex number such that and . Then the value of is equal to
- A.37
- B.42
- C.50
- D.61
Correct answer: C
Explanation: The circles centred (6,0) and (-2,6) (distance 10, radii 5) touch at ; , ; value .
Question 5
Mathematics · 4 marks · −1Let A, B and C be three matrices with real entries such that and . If and , then is
- A.4
- B.0
- C.-2
- D.2
Correct answer: B
Explanation: and commute, so : , gives , .
Question 6
Mathematics · 4 marks · −1The common difference of the A.P.: is 13 more than the common difference of the A.P.: . If , and , then is equal to
- A.16
- B.19
- C.24
- D.21
Correct answer: B
Explanation: , : .
Question 7
Mathematics · 4 marks · −1A bag contains 10 balls out of which k are red and are black, where . If three balls are drawn at random without replacement and all of them are found to be black, then the probability that the bag contains 1 red and 9 black balls is:
- A.
- B.
- C.
- D.
Correct answer: C
Explanation: Equal priors: .
Question 8
Mathematics · 4 marks · −1The mean and variance of 10 observations are 9 and 34.2, respectively. If 8 of these observations are 2, 3, 5, 10, 11, 13, 15, 21, then the mean deviation about the median of all the 10 observations is
- A.4
- B.6
- C.5
- D.7
Correct answer: C
Explanation: Missing pair sums to 10 with squares summing to 58: 3 and 7. Median 8.5; mean deviation .
Question 9
Mathematics · 4 marks · −1Let . Let x be the number of 9-digit numbers formed using the digits of the set S such that only one digit is repeated and it is repeated exactly twice. Let y be the number of 9-digit numbers formed using the digits of the set S such that only two digits are repeated and each of these is repeated exactly twice. Then,
- A.
- B.
- C.
- D.
Correct answer: A
Explanation: , ; .
Question 10
Mathematics · 4 marks · −1Let ABC be an equilateral triangle with orthocenter at the origin and the side BC on the line . If the co-ordinates of the vertex A are , then the greatest integer less than or equal to is
- A.2
- B.4
- C.5
- D.3
Correct answer: B
Explanation: A lies on the normal through O at twice the distance on the opposite side: ; , floor 4.
Question 11
Mathematics · 4 marks · −1Let be the equation of a chord of the circle (in the closed half-plane ) of diameter 10 passing through the origin. Let be another circle described on the given chord as its diameter. If the equation of the chord of the circle , which passes through the point (2, 3) and is farthest from the center of , is , then is equal to
- A.-2
- B.10
- C.-6
- D.6
Correct answer: A
Question 12
Mathematics · 4 marks · −1If , , then
- A.tan A, tan B, tan C are in G.P.
- B.tan A, tan C, tan B are in G.P.
- C.tan A, tan B, tan C are in A.P.
- D.tan A, tan C, tan B are in A.P.
Correct answer: B
Question 13
Mathematics · 4 marks · −1If the distances of the point from the line along the lines and are equal, then is equal to
- A.5
- B.6
- C.4
- D.7
Correct answer: D
Question 14
Mathematics · 4 marks · −1For three unit vectors satisfying and , the positive value of k is
- A.3
- B.6
- C.4
- D.5
Correct answer: D
Explanation: The condition forces , so ; .
Question 15
Mathematics · 4 marks · −1The value of is
- A.1/e
- B.2/e
- C.
- D.e/2
Correct answer: A
Explanation: ; with : .
Question 16
Mathematics · 4 marks · −1Let f be a polynomial function such that , for all . Then is equal to
- A.
- B.
- C.
- D.
Correct answer: C
Explanation: ; .
Question 17
Mathematics · 4 marks · −1The area of the region is
- A.
- B.
- C.
- D.
Correct answer: D
Explanation: In y: .
Question 18
Mathematics · 4 marks · −1The value of is equal to
- A.
- B.
- C.
- D.
Correct answer: D
Explanation: Numerator ; denominator ; ratio .
Question 19
Mathematics · 4 marks · −1Let be the solution of the differential equation , . If , then is equal to
- A.
- B.
- C.
- D.
Correct answer: C
Explanation: With : ; , from ; .
Question 20
Mathematics · 4 marks · −1If , where C is the constant of integration, then is equal to
- A.
- B.
- C.
- D.
Correct answer: C
Explanation: (differentiate to check); , ; difference .
Question 21
Mathematics · 4 marks · −1In a G.P., if the product of the first three terms is 27 and the set of all possible values for the sum of its first three terms is , then is equal to ______.
Correct answer: 90
Explanation: Terms : sum ; .
Question 22
Mathematics · 4 marks · −1If , then the number of solutions of the equation is ______
Correct answer: 1
Question 23
Mathematics · 4 marks · −1The value of is ______
Correct answer: 210
Explanation: for integer r, so each term is r: .
Question 24
Mathematics · 4 marks · −1For some , let the eccentricity and the length of the latus rectum of the hyperbola be and , respectively, and let the eccentricity and the length of the latus rectum of the ellipse be and , respectively. If , then is equal to ______
Correct answer: 8
Question 25
Physics · 4 marks · −1When both jaws of vernier callipers touch each other, zero mark of the vernier scale is right to zero mark of main scale, 4 mark on vernier scale coincides with certain mark on the main scale. While measuring the length of a cylinder, observer observes 15 divisions on main scale and 5 division of vernier scale coincides with a main scale division. Measured length of cylinder is ______ mm. (Least count of Vernier calliper = 0.1 mm)
- A.15.4
- B.15.5
- C.15.9
- D.15.1
Correct answer: D
Explanation: Zero error mm; reading ; corrected mm.
Question 26
Physics · 4 marks · −1In the potentiometer, when the cell in the secondary circuit is shunted with 4 resistance, the balance is obtained at the length 120 cm of wire. Now when the same cell is shunted with 12 resistance, the balance is shifted to a length of 180 cm. The internal resistance of cell is ______
- A.12
- B.4
- C.6
- D.3
Correct answer: B
Explanation: .
Question 27
Physics · 4 marks · −1A particle of mass m falls from rest through a resistive medium having resistive force, , where v is the velocity of the particle and k is a constant. Which of the following graphs represents velocity (v) versus time (t)?

- A.Rises from zero and saturates at a terminal value
- B.Rises ever more steeply (concave up)
- C.Straight line through the origin
- D.Decays from a high value toward zero
Correct answer: A
Explanation: .
Question 28
Physics · 4 marks · −1A block of mass 5 kg is moving on an inclined plane which makes an angle of with the horizontal. Friction coefficient between the block and inclined plane surface is . The force to be applied on the block so that the block will move down without acceleration is ______ N. ( m/s).
- A.7.5
- B.15
- C.25
- D.12.5
Correct answer: D
Explanation: Friction N; gravity component 25 N; push needed N.
Question 29
Physics · 4 marks · −1Water drops fall from a tap on the floor, 5 m below, at regular intervals of time, the first drop strikes the floor when the sixth drop begins to fall. The height at which the fourth drop will be from ground, at the instant when the first drop strikes the ground is ______ m. ( m/s)
- A.4.0
- B.3.8
- C.4.2
- D.2.5
Correct answer: C
Explanation: First drop falls for , fourth for : fallen m; height 4.2 m.
Question 30
Physics · 4 marks · −1Two circular discs of radius each 10 cm are joined at their centres by a rod of length 30 cm and mass 600 gm as shown in figure. If the mass of each disc is 600 gm and applied torque between two discs is dyne.cm, the angular acceleration of the discs about the given axis AB is ______ rad/s.

- A.22
- B.100
- C.27
- D.11
Correct answer: D
Explanation: About AB: discs ; rod ; total g cm; rad/s.
Question 31
Physics · 4 marks · −1Two wires A and B made of different materials of lengths 6.0 cm and 5.4 cm, respectively and area of cross sections m and m, respectively are stretched by the same magnitude under a given load. The ratio of the Young's modulus of A to that of B is x : 3. The value of x is ______.
- A.5
- B.4
- C.2
- D.1
Correct answer: A
Explanation: : .
Question 32
Physics · 4 marks · −110 kg of ice at C is added to 100 kg of water to lower its temperature from C. Consider no heat exchange to surroundings. The decrement to the temperature of water is ______ C. (specific heat of ice = 2100 J/Kg.C, specific heat of water = 4200 J/Kg.C, latent heat of fusion of ice J/Kg)
- A.15
- B.10
- C.11.6
- D.6.67
Correct answer: B
Explanation: C; decrement 10.
Question 33
Physics · 4 marks · −1In the following p-V diagram the equation of state along the curved path is given by where a is a constant. The total work done in the closed path is

- A.
- B.
- C.
- D.
Correct answer: A
Explanation: ; enclosed area ; the cycle is anticlockwise, so work is .
Question 34
Physics · 4 marks · −1Which of the following best represents the temperature versus heat supplied graph for water, in the range of C to C ?

- A.Plateau only at 100 °C
- B.No plateaus (straight line)
- C.Plateau at 0 °C (shorter) and at 100 °C (longer), sloped segments between
- D.Three plateaus including one above 100 °C
Correct answer: C
Question 35
Physics · 4 marks · −1The magnetic field at the centre of a current carrying circular loop of radius R is 16 T. The magnetic field at a distance on its axis from the centre is ______ T.
- A.4
- B.8
- C.
- D.2
Correct answer: D
Explanation: T.
Question 36
Physics · 4 marks · −1For the two cells having same EMF E and internal resistance r, the current passing through the external resistor 6 is same when both the cells are connected either in parallel or in series. The value of internal resistance r is ______ .
- A.9
- B.3
- C.6
- D.4
Correct answer: C
Explanation: ().
Question 37
Physics · 4 marks · −1The electric current in the circuit is given as . The r.m.s current for the period to is ______.
- A.
- B.
- C.
- D.
Correct answer: D
Question 38
Physics · 4 marks · −1Three long straight wires carrying current are arranged mutually parallel as shown in the figure. The force experienced by 15 cm length of wire Q is ______. ( T.m/A)

- A. N towards P
- B. N towards P
- C. N towards R
- D. N towards R
Correct answer: D
Explanation: P repels Q (antiparallel): N toward R; R attracts Q: N toward R. Total N toward R.
Question 39
Physics · 4 marks · −1Two point charges of 1 nC and 2 nC are placed at the two corners of equilateral triangle of side 3 cm. The work done in bringing a charge of 3 nC from infinity to the third corner of the triangle is ______ J. N.m/C
- A.5.4
- B.27
- C.3.3
- D.2.7
Correct answer: D
Explanation: J.
Question 40
Physics · 4 marks · −1The electric field of an electromagnetic wave travelling through a medium is given by then the refractive index of the medium is ______. (All given measurement are in SI units)
- A.1.7
- B.1.5
- C.1.2
- D.2
Correct answer: B
Explanation: m/s, .
Question 41
Physics · 4 marks · −1Given below are two statements: Statement I: A plane wave after passing through prism remains as plane wave but passing through small pin hole may become spherical wave. Statement II: The curvature of a spherical wave emerging from a slit will increase for increasing slit width. In the light of the above statements, choose the correct answer from the options given below
- A.Both Statement I and Statement II are false
- B.Both Statement I and Statement II are true
- C.Statement I is false but Statement II is true
- D.Statement I is true but Statement II is false
Correct answer: D
Question 42
Physics · 4 marks · −1The magnitudes of power of a biconvex lens (refractive index 1.5) and that of a plano-concave lens (refractive index = 1.7) are same. If the curvature of plano-concave lens exactly matches with the curvature of back surface of the biconvex lens, then ratio of radius of curvature of front and back surface of the biconvex lens is ______.
- A.5 : 2
- B.5 : 12
- C.12 : 5
- D.2 : 5
Correct answer: A
Explanation: , .
Question 43
Physics · 4 marks · −1An atom is bombarded by shower of fundamental particles and in 10 s this atom absorbed 10 electrons, 10 protons and 9 neutrons. The percentage growth in the surface area of the nucleons is recorded by:
- A.150 %
- B.250%
- C.900%
- D.225%
Correct answer: D
Explanation: A: 8 to 27, : 2 to 3, area ratio 9/4; NTA key gives 225% (the new area as a percentage of the old).
Question 44
Physics · 4 marks · −1Assuming in forward bias condition there is a voltage drop of 0.7 V across a silicon diode, the current through diode in the circuit is ______ mA. (Assume all diodes in the given circuit are identical)

- A.11.7
- B.17.6
- C.20.15
- D.18.8
Correct answer: D
Explanation: mA shared by D1 and D3: 18.8 mA.
Question 45
Physics · 4 marks · −1A convex lens of refractive index 1.5 and focal length cm is immersed in water. The difference in focal lengths of the given lens when it is in water and in air is . The value of is ______. (refractive index of water = 4/3)
Correct answer: 3
Explanation: cm; difference .
Question 46
Physics · 4 marks · −1The equivalent resistance between the points A and B in the following circuit is . The value of x is ______.

Correct answer: 21
Explanation: Node analysis (, ): , ; current , so .
Question 47
Physics · 4 marks · −1The ratio of de Broglie wavelength of a deutron with kinetic energy E to that of an alpha particle with kinetic energy 2E, is n : 1. The value of n is ______. (Assume mass of proton = mass of neutron) :
Correct answer: 2
Explanation: : .
Question 48
Physics · 4 marks · −1A solid sphere of radius 10 cm is rotating about an axis which is at a distance 15 cm from its centre. The radius of gyration about this axis is cm. The value of n is
Correct answer: 265
Explanation: .
Question 49
Physics · 4 marks · −1The displacement of a particle, executing simple harmonic motion with time period T, is expressed as , where A is the amplitude. The maximum value of potential energy of this oscillator is found at . The value of is ______.
Correct answer: 2
Explanation: PE is maximum at , first at : .
Question 50
Chemistry · 4 marks · −1Figure 1 shows the electron probability density for the 2s orbital with a spherical nodal surface; Figure 2 shows the wave function along +x with marked points A, B, C and D. Which of the following point in Figure 2 most accurately represents the nodal surface as shown in Figure 1?

- A.C
- B.D
- C.B
- D.A
Correct answer: C
Explanation: The radial node is where changes sign: point B.
Question 51
Chemistry · 4 marks · −1The wave numbers of three spectral lines of H atom are considered. Identify the set of spectral lines belonging to Balmer series. (R = Rydberg constant)
- A.
- B.
- C.
- D.
Correct answer: D
Explanation: for n = 3, 4, 5: .
Question 52
Chemistry · 4 marks · −1Given below are two statements: Statement I: The number of species among BF, SiF, XeF and SF, that have unequal EF bond lengths is two. Here, E is the central atom. Statement II: Among O, O, F and O, O has the highest bond order. In the light of the above statements, choose the correct answer from the options given below
- A.Both Statement I and Statement II are true
- B.Statement I is false but Statement II is true
- C.Both Statement I and Statement II are false
- D.Statement I is true but Statement II is false
Correct answer: C
Explanation: Only SF (see-saw) has unequal bonds (I false); O (2.5) has the highest bond order (II false).
Question 53
Chemistry · 4 marks · −120.0 dm of an ideal gas 'X' at 600 K and 0.5 MPa undergoes isothermal reversible expansion until pressure of the gas is 0.2 MPa. Which of the following option is correct? (Given: log 2 = 0.3010 and log 5 = 0.6989)
- A.w = $-$3.9 kJ, U = 0, H = 0; q = 3.9 kJ
- B.w = 9.1 J, U = 9.1 J, H = 0; q = 0
- C.w = $-$9.1 kJ, U = 0, H = 0, q = 9.1 kJ
- D.w = +4.1 kJ, U = 0 , H = 0; q = $-$4.1 kJ
Correct answer: C
Explanation: kJ.
Question 54
Chemistry · 4 marks · −1At T(K), 2 moles of liquid A and 3 moles of liquid B are mixed. The vapour pressure of ideal solution formed is 320 mm Hg. At this stage, one mole of A and one mole of B are added to the solution. The vapour pressure is now measured as 328.6 mm Hg. The vapour pressure (in mm Hg) of A and B are respectively:
- A.600, 400
- B.500, 200
- C.400, 300
- D.300, 200
Correct answer: B
Explanation: , , .
Question 55
Chemistry · 4 marks · −1Consider a weak base 'B' of p = 5.699. 'x' mL of 0.02 M HCl and 'y' mL of 0.02 M weak base 'B' are mixed to make 100 mL of a buffer of pH 9 at 25 C. The values of 'x' and 'y' respectively are: [Given: log 2 = 0.3010, log 3 = 0.4771, log 5 = 0.699]
- A.x = 42.7, y = 57.3
- B.x = 11.1, y = 88.9
- C.x = 85.7, y = 14.3
- D.x = 14.3, y = 85.7
Correct answer: D
Explanation: pOH 5 = 5.699 + log(salt/base): salt/base = 0.2, i.e. with : x = 14.3, y = 85.7.
Question 56
Chemistry · 4 marks · −1An organic compound undergoes first order decomposition. The time taken for decomposition to and of its initial concentration are and respectively. What is the value of ? (log 2 = 0.3)
- A.3
- B.30
- C.9
- D.0.9
Correct answer: C
Explanation: .
Question 57
Chemistry · 4 marks · −1In period 4 of the periodic table, the elements with highest and lowest atomic radii are respectively.
- A.K & Se
- B.K & Br
- C.Rb & Br
- D.Na & Cl
Correct answer: B
Question 58
Chemistry · 4 marks · −1Regarding the hydrides of group 15 elements EH (E = N, P, As, Sb), select the correct statement from the following: A. The stability of hydrides decreases down the group. B. The basicity of hydrides decreases down the group. C. The reducing character increases down the group. D. The boiling point increases down the group. Choose the correct answer from the options given below:
- A.A, B, C & D
- B.A, B & C only
- C.B & C only
- D.A & D only
Correct answer: B
Question 59
Chemistry · 4 marks · −1The correct statement among the following is:
- A.Ni(CO) is diamagnetic and [NiCl] and [Ni(CN)] are paramagnetic.
- B.Ni(CO) and [NiCl] are diamagnetic and [Ni(CN)] is paramagnetic.
- C.[Ni(CN)] and [NiCl] are diamagnetic and Ni(CO) is paramagnetic.
- D.Ni(CO) and [Ni(CN)] are diamagnetic and [NiCl] is paramagnetic.
Correct answer: D
Question 60
Chemistry · 4 marks · −1Given below are two statements: Statement I: The number of pairs, from the following, in which both the ions are coloured in aqueous solution is 3. [Sc, Ti], [Mn, Cr], [Cu, Zn] and [Ni, Ti]. Statement II: Th is the strongest reducing agent among Th, Ce, Gd and Eu. In the light of the above statements, choose the correct 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 false
- D.Both Statement I and Statement II are true
Correct answer: C
Explanation: Only [Mn, Cr] has both coloured (I false); Eu is the strongest reductant (II false).
Question 61
Chemistry · 4 marks · −1Method used for separation of mixture of products (B and C) obtained in the following reaction is: Benzene + Br A B + C
- A.simple distillation
- B.sublimation
- C.fractional distillation
- D.steam distillation
Correct answer: C
Explanation: B and C are o- and p-bromonitrobenzene; NTA key: fractional distillation.
Question 62
Chemistry · 4 marks · −1CORRECT order of stability for the following is CH=CH, CHCH, CHC
- A.CHC > CH=CH > CHCH
- B.CHCH > CH=CH > CHC
- C.CH=CH > CHC > CHCH
- D.CHC > CHCH > CH=CH
Correct answer: A
Question 63
Chemistry · 4 marks · −1PhCH=CH Product. Consider the above reaction. A. The reaction proceeds through a more stable radical intermediate. B. The role of peroxide is to generate H (Hydrogen radical). C. During this reaction, benzene is formed as a byproduct. D. 1Bromo$--$phenylethane is formed as the minor product. E. The same reaction in absence of peroxide proceeds via carbocation intermediate. Identify the correct statements. Choose the correct answer from the options given below:
- A.A, B & D Only
- B.C, D & E Only
- C.A, C & E Only
- D.A & E Only
Correct answer: C
Question 64
Chemistry · 4 marks · −1Given below are two statements for the following reaction sequence. Compound 'X' (molecular formula CHCl) Compound 'Y'; Y Compound 'Z'; Y Compound 'Q' (Molecular formula CH). Statement I: Compound 'Z' will give yellow precipitate with NaOI. Statement II: Compound 'Q' has two different types of 'H' atoms (aromatic : aliphatic) in the ratio 1:3. In the light of the above statements, choose the correct answer from the options given below:
- A.Both Statement I and Statement II are true
- B.Statement I is false but Statement II is true
- C.Statement I is true but Statement II is false
- D.Both Statement I and Statement II are false
Correct answer: A
Explanation: Y = propyne; Z = acetone (iodoform positive); Q = mesitylene (3 aromatic H : 9 CH H = 1:3).
Question 65
Chemistry · 4 marks · −1Consider the following reaction sequence: Compound (x) [76.6% C, 6.38% H, vapour density 47] Compound (y) (Major Product). Compound (y) develops characteristic colour with neutral FeCl solution. Identify the INCORRECT statement from the following for the above sequence.
- A.Compound y will dissolve in NaHCO and evolve a gas.
- B.Both compounds x and y will burn with sooty flame.
- C.Compound x is more acidic than compound y.
- D.Both compounds x and y will dissolve in NaOH.
Correct answer: C
Explanation: x = phenol, y = salicylic acid (Kolbe); salicylic acid is more acidic than phenol.
Question 66
Chemistry · 4 marks · −1Given below are the four isomeric compounds (P, Q, R, S): P = 1-phenylprop-2-en-1-ol (PhCH(OH)CH=CH); Q = 3-phenylpropanal (PhCHCHCHO); R = phenylacetone (PhCHCOCH); S = propiophenone (PhCOCHCH). Identify correct statements from below. A. Q, R and S will give precipitate with 2, 4 DNP. B. P and Q will give positive Bayer's test. C. Q and R will give sooty flame. D. R and S will give yellow precipitate with I / NaOH. E. Q alone will deposit silver with Tollen's reagent. Choose the correct option.

- A.A, B, D and E only
- B.C and E only
- C.A and E only
- D.A, C and E only
Correct answer: D
Question 67
Chemistry · 4 marks · −1Consider the following reactions giving major product. Identify the correct reaction.
- A.Potassium phthalimide + CHX, (i) heat (ii) hydrolysis CHNH
- B.CHCHNH CHCHNC CHCHNH
- C.CHNHCOCH product nitrated at the para position of the benzoyl ring
- D.CHCHCONH + Br + 4KOH (alc) CHCHNH + 2KBr + KCO + 2HO
Correct answer: D
Explanation: Hofmann bromamide degradation, correctly balanced.
Question 68
Chemistry · 4 marks · −1In the given pentapeptide, find out an essential amino acid (Y) and the sequence present in the pentapeptide: HNCH(CH(OH)CH)CONHCH(CHOH)CONHCH(CHCOOH)CONHCHCONHCH(CH)COOH.
- A.Y = Threonine; ThrSerAspGlyAla
- B.Y = Serine; SerAspThrAlaGly
- C.Y = Serine; ThrSerAspAlaGly
- D.Y = Threonine; SerThrAspGlyAla
Correct answer: A
Question 69
Chemistry · 4 marks · −1Given below are two statements: Statement I: GrissIlosvay test is used for the detection of nitrite ion, which involves the use of sulphanilic acid and naphthylamine reagent. Statement II: In the above test, sulphanilic acid is diazotized by the acidified nitrite ion, which on further coupling with naphthylamine forms an azodye. In the light of the above statements, choose the correct answer from the options given below
- A.Statement I is false but Statement II is true
- B.Both Statement I and Statement II are true
- C.Both Statement I and Statement II are false
- D.Statement I is true but Statement II is false
Correct answer: B
Question 70
Chemistry · 4 marks · −1X is the number of geometrical isomers exhibited by [Pt(NH)(HO)BrCl]. Y is the number of optically inactive isomer(s) exhibited by [CrCl(ox)]. Z is the number of geometrical isomers exhibited by [Co(NH)(NO)]. The value of X + Y + Z is ______.
Correct answer: 6
Explanation: X = 3 (square planar Mabcd), Y = 1 (trans isomer), Z = 2 (fac, mer): 6.
Question 71
Chemistry · 4 marks · −10.53 g of an organic compound (x) when heated with excess of nitric acid (concentrated) and then with silver nitrate gave 0.75 g of silver bromide precipitate. 1.0 g of (x) gave 1.32 g of CO gas on combustion. The percentage of hydrogen in the compound (x) is ______%. [Nearest Integer] [Given: Molar mass in g mol H : 1, C : 12, Br : 80, Ag : 108, O : 16 ; Compound (x) : CHBr]
Correct answer: 4
Explanation: Br 60.2%, C 36%, H by difference 3.8%, i.e. 4.
Question 72
Chemistry · 4 marks · −1500 mL of 1.2 M KI solution is mixed with 500 mL of 0.2 M KMnO solution in basic medium. The liberated iodine was titrated with standard 0.1 M NaSO solution in the presence of starch indicator till the blue color disappeared. The volume (in L) of NaSO consumed is ______. (Nearest integer)
Correct answer: 3
Explanation: In basic medium MnOMnO (3 e): 0.1 mol mol e gives 0.15 mol I (KI 0.6 mol in excess); thiosulphate 0.3 mol = 3 L.
Question 73
Chemistry · 4 marks · −1Consider the following redox reaction taking place in acidic medium BH(aq) + ClO(aq) HBO(aq) + Cl(aq). If the Nernst equation for the above balanced reaction is , then the value of n is ______. (Nearest integer)
Correct answer: 24
Explanation: BH loses 8 e (H: ), ClO gains 6: balanced 3BH + 4ClO, n = 24.
Question 74
Chemistry · 4 marks · −1Consider the dissociation equilibrium of the following weak acid HA H(aq) + A(aq). If the pKa of the acid is 4, then the pH of 10 mM HA solution is ______. (Nearest integer) [Given: The degree of dissociation can be neglected with respect to unity]
Correct answer: 3
Explanation: pH .