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Mere Teacher · Previous Year Questions
JEE Main Chemistry · Atomic Structure · Set 8 (Q211-240)
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211.
How many orbitals is/are possible with n=3,l=1 and ml=−1 value?
(1)2
(2)3
(3)5
(4)1
212.
The radius of the 2nd orbit of Li2+ is x. The expected radius of the 3rd orbit of Be3^ is
(1)49x
(2)94x
(3)1627x
(4)2716x
213.
For azimuthal quantum number l=3, the maximum number of electrons will be
(1)2
(2)6
(3)0
(4)14
214.
If a suitable photon is employed to locate an electron (mass (=9.11×10−31kg) in an atom within a distance of 10.98nm, the uncertainty involved in the measurement of its velocity in ms−1 is
(1)π1.6565×106
(2)π1.6565×104
(3)1.6565×10−8π
(4)π1.6565×108
215.
If Δx is the uncertainity in position and Δv is the uncertainity in velocity of a particle are equal, the correct expression for uncertainity in momentum for the same particle is
(1)41πmh
(2)312πmh
(3)21πmh
(4)21mπh
216.
The number of s-electrons present in an ion with 55 protons in its unipositive state is
(1)8
(2)9
(3)12
(4)10
217.
Which of the following is/are not correct with respect to energy of atomic orbitals of hydrogen atom? (A) 1s<2p<3d<4s (B) 1s<2s=2p<3s=3p (C) 1s<2s<2p<3s<3p (D) 1s<2s<4s<3d Choose the correct answer from the options given below :
(1)(A) and (C) only
(2)(B) and (D) only
(3)(C) and (D) only
(4)(A) and (B) only
218.
What is the work function of the metal if the light of wavelength 4000Å generates photoelectrons of velocity 6×105ms–1 from it ? (Mass of electron = 9 × 10–31 kg, Velocity of light = 3×108ms–1, Plank's constant = 6.626 ×10–34 Js, Charge of electron = 1.6 ×10–19JeV–1)
(1)3.1 eV
(2)0.9 eV
(3)4.0 eV
(4)2.1 eV
219.
Energy of H-atom in the ground state is –13.6 eV, hence energy in the second excited state is :
(1)– 6.8 eV
(2)– 3.4 eV
(3)– 1.51 eV
(4)– 4.53 eV
220.
The figure that is not a direct manifestation of the quantum nature of atoms is
(1)
(2)
(3)
(4)
221.
Match the following pairs. Species Number of electrons (A) O2− (i) 18 (B) Li2+ (ii) 2 (C) He (iii) 10 (D) Ca++ (iv) 1
(1)(A) - (i), (B) - (ii), (C) - (iv), (D) - (iii)
(2)(A) - (ii), (B) - (iii), (C) - (i), (D) - (iv)
(3)(A) - (iii), (B) - (iv), (C) - (ii), (D) - (i)
(4)(A) - (iv), (B) - (i), (C) - (iii), (D) - (ii)
222.
Impossible orbital among the following is
(1)2s
(2)3f
(3)2p
(4)4d
223.
The orbit having Bohr radius equal to 1st Bohr orbit of H–atom is:
(1)n = 2 of He+
(2)n = 2 of B+4
(3)n = 3 of Li+2
(4)n = 2 of Be+3
224.
The ratio of the shortest wavelength of two spectral series of hydrogen spectrum is found to be about 9. The spectral series are:
(1)Lyman and Paschen
(2)Balmer and Brackett
(3)Brackett and Pfund
(4)Paschen and Pfund
225.
If λ0 and λ be the threshold wavelength and wavelength of incident light, the velocity of photoelectron ejected from the metal surface is :
(1)m2h(λ0−λ)
(2)m2hc(λ0−λ)
(3)m2hc(λλ0λ0−λ)
(4)m2h(λ01−λ1)
226.
Given,(A) n=5,ml=−1(B) n=3,l=2,ml=−1,ms=+21 The maximum number of electron(s) in an atom that can have the quantum numbers as given in (A) and (B) respectively are:
(1)8 and 1
(2)2 and 4
(3)26 and 1
(4)4 and 1
227.
If radius of second Bohr orbit of the He+ion is 105.8 pm , what is the radius of third Bohr orbit of Li2+ ion?
(1)15.87 pm
(2)1.587 pm
(3)158.7Å
(4)158.7 pm
228.
The de Broglie wavelength of a particle with mass 1 g and velocity 100 m/s is
(1)6. 63×10−35m
(2)6. 63×10−34m
(3)6. 63×10−33m
(4)6. 65×10−35m
229.
The orientation of an atomic orbital is governed by
(1)principal quantum number
(2)azimuthal quantum number
(3)spin quantum number
(4)magnetic quantum number
230.
According to Bohr’s theory, the angular momentum to an electron in 5th orbit is :
(1)25πh
(2)1.0πh
(3)10πh
(4)2.5πh
231.
Calculate the wave number and frequency of orange radiation having wavelength 6300Å.
(1)1.587×108m−1,4.761×1016s−1
(2)1.587×104m−1,4.761×1014s−1
(3)1.587×106m−1,4.761×1014s−1
(4)1.587×106m−1,4.761×1016s−1
232.
The number of radial nodes, angular nodes of a 4f− orbital are respectively
(1)0,3
(2)1,2
(3)2,1
(4)2,0
233.
The energy of an electron in first Bohr orbit of H-atom is –13.6 eV. The energy value of electron in the excited state of Li2+ is :
(1)– 27.2 eV
(2)30.6 eV
(3)– 30.6 eV
(4)27.2 eV
234.
Maximum number of electrons possible with spin quantum number +21 with principal quantum number n=4 in an atom is
(1)16
(2)9
(3)4
(4)25
235.
In an atom, an electron is moving with a speed of 600 m/s with an accuracy of 0.005%. Certainity with which the position of the electron can be located is (h = 6.6 × 10–34 kg m2s–1, mass of electron, em = 9.1 × 10–31 kg):
(1)5.10 × 10–3 m
(2)1.92 × 10–3 m
(3)3.83 × 10–3 m
(4)1.52 × 10–4 m
236.
The wavelength of a microscopic particle of mass 9.1×10−31kg is 182nm, its kinetic energy in J is (h=6.625×10−34Js)
(1)7.28×10−23
(2)7.28×10−24
(3)3.64×10−23
(4)3.64×10−24
237.
The ratio of the radius of second orbit of Li2+ to that of third orbit of Be3+ is
(1)89
(2)98
(3)1627
(4)2716
238.
The minimum uncertainty in the speed of an electron in an one dimensional region of length 2a0 (Where a0 = Bohr radius 52.9 pin) is_____km s−1.(Given : Mass of electron = 9.1 x 10−31 kg, Planck's constant h = 6.63 x 10−34 Js)
239.
Values of work function (W0) for a few metals are given below Metal Li Na K Mg Cu Ag 2.42 2.3 2.25 3.7 4.8 4.3 The number of metals which will show photoelectric effect when light of wavelength 400 nm falls on it is_____ Given: h = 6. 6 x 10−34 J s c = 3 x 108ms−1 e = 1.6 x 10−19 C
240.
A 50 watt bulb emits monochromatic red light of wavelength of 795 nm . The number of photons emitted per second by the bulb is x×1020. The value of x is. (Nearest integer) [Given: h=6.63×10−34J and c=3.0×108ms−1 ]
