JEE Main Model Questions

Here we are giving model practice questions from Physical Chemistry for JEE Main candidates. JEE Main is going to be conducted by IITs JEE Baord for admission into Engineering programmes in IITs and NITs along with several deemed universities and participating colleges.

1. Assertion (A) : Cupric copper is paramagnetic Reason (R) : Charge of one mole of cupric is two Faradays
1) Both A and R are true, R properly explains A
2) Both A and R are true, R does not explain A
3) A is true, but R is false
4) A is false, but R is true

2. In one of the Bohr’s hydrogen orbit electron revolving with a wavelength of 10A0. The kinetic energy of the electron is
1) 13.6 eV 2) 10.2 eV
3) 3.4 eV 4) 1.5 eV

3. If R is Rydberg constant the wave length of first line in Balmer series of hydrogen emission spectrum is

4. In order to fill all the electrons of chromium (Z=24), number of orbitals required per atom is
1) 12 2) 13 3) 15 4) 24

5. Bond length of HCl is 1.275A° and experimental dipolemoment is 1.03D. The percentage ionic character of HCl is approximately
1) 16.8 2) 50.2 3) 66.7 4) 92.4

6. Aluminum fluoride is more ionic than aluminum chloride. This is because
1) Al is trivalent
2) Al3+ has high polarisation ability
3) F– is small in size
4) Cl – is less polarised

7. The ratio of pure and hybrid orbitals used for bonding in ethylene molecule
1) 1 : 1 2) 1 : 3 3) 3 : 1 4) 3 : 2

8. Ionic, covalent, dative and hydrogen bonds are all present in
1) ammonium chloride
2) epsom salt
3) potassium ferricyanide
4) sodium cyanide

9. Observe the following combinations
A : AB3E – NH3 – Pyramidal
B : AB4E2 – XeF4 – square planar
C : AB4 – CCl4– tetrahedral
D : AB2E2 –SnCl2 – angular

1) A, B, D are correct
2) A, C, D, are correct
3) B, C, D are correct
4) A, B, C are correct.

10. A open vessel at 27°C is heated until 1/4th of the air in it has been expelled. Assuming that the volume of the vessel remains
same, the temperature at which the vessel was heated is
1) 127°C 2) 177°C 3) 427°C 4) 477°C

12. van der Waals’ constants ‘a’ in atm L2 mol–2 and ‘b’ in L mol –1 are given for four gases : a = 4.17 and b = 0.037 for NH3 a = 1.39 and b = 0.032 for N2 a = 1.35 and b = 0.032 for Ar a = 3.99 and b = 0.042 for CO2 The change of state will be relatively easy for the gas
1) NH3 2) N2 3) Ar 4) CO2

13. Mayer’s relation Cp – Cv = R, can be applied for noble gases. Then the molar heat capacities at constant pressure and at constant volume are respectively
1) 1.5 R and 2.5 R 2) 2.5 R and 3.5 R
3) 3.5 R and 4.5 R 4) 4.5 R and 5.5 R

14. Under similar condition, the liquid that has highest vapour pressure among the following is
1) Diethyl ether 2) Ethanol
3) Acetic acid 4) Water

15. Packing density in the case of metal with face centered cubic structure is
1) 73% 2) 68% 3) 52% 4) 43%

16. Select the correct among the following statements
A) Na2O has 4 : 8 coordination
B) ZnS has 4 : 4 coordination
C) NaCl has 6 : 6 coordination
D) CaF2 has 8 : 4 coordination

1) A, B, C 2) A, B, D
3) A, C, D 4) A, B, C, D

17. 17 grams of hydrogen peroxide is present in 560ml of aqueous solution. This solution is called
1) 10 volumes
2) 17 volumes
3) 20 volumes
4) 34 volumes

18. Molecular weight of a bivalent metal chloride is 136.4. Then equivalent weight of the metal is
1) 26.2 2) 32.7 3) 52.4 4) 65.4

19. Polythene is formed according to the equation nH2C = CH2 → (H2C – CH2)n. If 1000g of ethylene is taken, the mass of polythene formed is 1000
1) 1000g 2) g 3) 1000n g 4)ngn

20. An oxide of metal (M) has mass of oxygen 40%. If the atomic weight of M is 24, the emperical formula of oxide is
1) M2O3 2) MO2 3) MO 4) M2O

21. 1024 molecules of a solute of molar mass 100 are dissolved in
1025 molecules of solvent of molar mass 18. The mole fraction of
solute in the mixture is
1) 0.01 2) 0.09 3) 0.5 4) 0.8

22. 100ml of pure phosphine is decomposed to produce phosphorous solid and hydrogen. Under similar conditions of measurement,
the volume
1) increases by 50ml 2) decreases by 50ml
3) increases by 150ml 4) decreases by 150ml N

23. Hydrazoic acid is represented as || N– H. N The oxidation numbers of nitrogen are
1) –1, –1, –1 2) –1, –1, 0
3) 0, 0, –1 4) –1, –1, +1

24. The mass of natural water that has one mole of deuterium oxide (called heavy water) is
1) 1.2 kg 2) 12 kg
3) 120 kg 4)1200 kg

25. Weight percentage of chlorine in an alkali metal chloride is 48%. The atomic weight of the metal is likely
1) 56 2) 39 3)19 4)7

26. Analysis of an organic compound gas 40% of carbon and 6.6% hydrogen by weight. The chemical formula of the compound may be
1) HCOOCH3 2) OHC – CHO
3) CH3 – CH2OH 4) CH3 – CHO

28. Regarding oxidation numbers, which of the following is false
1) Oxidation number of metal in metal carbonyl is zero
2) Oxidation number of oxygen in a super oxide is fractional
3) Fluorine exhibits –1 oxidation state
4) The sum of oxidation number of all atoms in an ion is equal to charge of ion

29. PbS + H2O2 → PbSO4 + H2O
In the balance equation of the above reaction, number of electrons transferred from each molecule of H2O2 to lead sulphide is
1) 1 2) 2 3) 4 4) 8

30. 2 grams of a mixture of Na2CO3 and NaHCO3 on strong heating has suffered a mass loss of 0.62 gram. Percent weight of Na2CO3 in the given mixture is
1) 16 2) 24 3) 32 4) 50.

KEY: 1) 2 2) 4 3) 3 4) 3 5) 1 6) 3 7) 1 8) 2 9) 4 10) 1 11) 3 12) 1 13) 3 14) 1 15) 1 16) 4 17) 1 18) 2 19) 1 20) 3 21) 2 22) 1 23) 3 24) 3 25) 2 26) 1 27) 3 28) 1 29) 2 30) 1.

Model Questions are given below for Physics subject. These are very much useful for the candidates going to appear for JEE Main Examinations in 2013 or later. The model questions were given along with key for the benefit of the students.

1. A liquid with volume expansion coefficient γ is filled in a container of material having linear expansion coefficient α. The liquid is found to over flow, when the temperature decreases by θo. Then
A) γ > 3α B) g > α C) g < 3α D) g < α 2. Two metal rods, A and B, have lengths l and 3l and linear expansion coefficient α and 2 α respectively. When the temperature decreases by θo C, it is found that their lengths are equal. Then A) α θ = 1/5 B) 2α θ = 5 C) 5α θ = 2 D) 5α θ = 3 3. An iron tyre is to be fitted onto a wooden wheel 1 m in diameter. The diameter of the tyre is 6 mm smaller than that of the wheel. The temperature of the tyre should be increased by a minimum (α = 3.6 × 10-5 oC-1 for iron). A) 1000 oC B) 334 oC C) 500 oC D) 167 oC 4. A metal sphere is heated. On thermal expansion, the smallest percentage increase will occur in its A) diameter B) volume C) surface area D) density 6. A particle is projected from point A with velocity u at an angle α with horizontal. In its parabolic path, at point P the particle is moving at right angles to its initial direction of projection. Its velocity at P is A) u tan α B) u cot α C) u cos α D) u cosec α 7. The angular speed of the second’s hand of a clock is A) (1/60) rad/s B) (π/60) rad/s C) (2π/60) rad/s D) (360/60) rad/s 8. A particle moves in a circle of radius 25 cm at two revolution per sec. The acceleration of the particle in m/s2 is A) π2 B) 8π2 C) 4π2 D) 2π2 9. A motor car is travelling at 60 m/s on a circular road of radius 1200 m. It is increasing its speed at the rate of 4 m/s2. The acceleration of the car is A) 3 m/s2 B) 4 m/s2 C) 5 m/s2 D) 7 m/s2 10. In a thermo dynamical process pressure of fixed mass of gas is changed in such a way that the gas molecules give out 30 J of heat and 10 J of work is done on the gas. If the internal energy of the gas was 40 J, the final internal energy will be A) zero B) 80 J C) 20 J D) – 20 J 11. A body travelling along a straight line traversed one third of the total distance with a velocity 4 m/s. The remaining part of the distance was covered with a velocity 2 m/s for half the time and with velocity 6 m/s for the other half of time. The mean velocity averaged over the whole time of motion is A) 5 m/s B) 4 m/s C) 4.5 m/s D) 3.5m/s 12. A ball is projected upwards from the foot of a tower. The ball crosses the top of the tower after an interval of 6s and the ball reaches the ground after 12s. The height of the tower (g = 10 m/s2) A) 120 m B) 135 m C) 175 m D) 80 m 16. A particle is projected from a horizontal plane (x-z plane). Such that its velocity vectors at time t is given by→ v = a i Λ + (b-ct) j Λ . Its range on the horizontal plane is A) ba/c B) 2ba/c C) 3ba/c D) none 17. A body is placed on a rough inclined plane of inclination θ. As the angle θ is increased from 0o to 90o the contact force between the block and the plane A) remains constant B) first remains constant then decreases C) first decreases then increases D) first increases then decreases 18. A flexible chain of weight W hangs between two fixed points A and B, which are at the same horizontal level. The inclination of the chain with the horizontal at both the points of support is θ. What is the tension of the chain at the mid point W W A) ___ cosec θ B) ___ tan θ 2 2 W C) ___ cot θ D) none 22. A particle of mass 1 kg is projected at an angle of 30o with horizontal with velocity v = 40 m/s. The change in linear momentum of the particle after time t = 1 s will be (g = 10 m/s2) A) 7.5 kg-m/s B) 15 kg-m/s C) 10 kg-m/s D) 20 kg-m/s 23. The centre of mass of a nonuniform rod of length L whose mass per unit length λ = Kx2/L, where K is a constant and x is the distance from one end is A) 3L/4 B) L/8 C) K/L D) 3K/l 24. From a circular disc of radius R a square is cut out with a radius as its diagonal. The distance of the centre of mass of the remainder from the centre of the disc is R R A) ______ B) ______ π - 2 π R R C) ______ D) ______ 2(2π - 1) 2 KEY : 1)C 2)C 3)D 4)A 5)C 6)B 7)C 8)C 9)C 10)C 11)B 12)B 13)B 14)C 15)D 16)B 17)B 18)C 19)C 20)C 21)A 22)C 23)A 24)C 25)B 26)A 27)A 28)C 29)B 30)C 31)C 32)B 33)D.