Atomic Structure PYQs Set 2 (PDF)

Set 2 of 14 · Questions 31-60 of 415

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Mere Teacher · Previous Year Questions JEE Main Chemistry · Atomic Structure · Set 2 (Q31-60)
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31. $Calculate the wavelength (in nanometer) associated with a proton moving at 1.0 \times 1 0^{3} m s^{-1} (Mass of proton = 1.67 \times 1 0^{-27} kg and h = 6.63 \times 1 0^{-34} Js):$ (1) $0.40 nm$ (2) $2.5 nm$ (3) $14.0 nm$ (4) $0.032 nm$ 32. $Maximum number of electrons that can be accommodated in shell with n = 4 are:$ (1) $16$ (2) $32$ (3) $50$ (4) $72$ 33. $Ionization energy of gaseous Na atom is 495.5 kJ m o l^{-1} . The lowest possible frequency of light that ionizes a sodium atom is (h = 6.626 \times 1 0^{-34} Js, N_{A} = 6.022 \times 1 0^{23} mol^{-1})$ (1) $7.50 \times 1 0^{4} s^{-1}$ (2) $4.76 \times 1 0^{14} s^{-1}$ (3) $3.15 \times 1 0^{15} s^{-1}$ (4) $1.24 \times 1 0^{15} s^{-1}$ 34. $Which of the following sets of quantum numbers is correct for an electron in 4 f orbital?$ (1) $n = 3, l = 2, m_{1} = - 2, m_{s} = + 1/2$ (2) $n = 4, l = 3, m_{1} = + 1, m_{s} = + 1/2$ (3) $n = 4, l = 3, m_{1} = + 4, m_{s} = + 1/2$ (4) $n = 4, l = 4, m_{1} = + 4, m_{s} = - 1/2$ 35. $The frequency of light emitted for the transition n = 4 to n = 2 of H e^{+} is equal to the transition in H atom corresponding to which of the following?$ (1) $n = 2 to n = 1$ (2) $n = 3 to n = 2$ (3) $n = 4 to n = 3$ (4) $n = 3 to n = 1$ 36. $The wave number of the spectral line in the emission spectrum of hydrogen will be equal to 8/9 times the Rydberg's constant if the electron jumps from$ (1) $n = 3 to n=1$ (2) $n = 10 to n=1$ (3) $n = 9 to n=1$ (4) $n = 2 to n=1$ 37. $The energies of an electron in first orbit of He^{+} and in third orbit of Li^{2 +} in J are respectively$ (1) $- 8.72 \times 10^{- 18}, - 2.18 \times 10^{- 18}$ (2) $- 8.72 \times 10^{- 18}, - 1.96 \times 10^{- 17}$ (3) $- 1.96 \times 10^{- 17}, - 2.18 \times 10^{- 18}$ (4) $- 8.72 \times 10^{- 17}, - 1.96 \times 10^{- 17}$ 38. $Based on equation E = - 2.178 \times 10^{- 18} J (\frac{z ^{2}}{n ^{2}}), certain conclusions are written. Which of them is not correct?$ (1) $Equation can be used to calculate the change in energy when the electron changes orbit.$ (2) $For n = 1, the electron has a more negative energy than it does for n = 6 which means that the electron is more loosely bound in the smallest allowed orbit.$ (3) $The negative sign in equation simply means that the energy of electron bound to the nucleus is lower than it would be if the electrons were at the infinite distance from the nucleus.$ (4) $Larger the value of n, the larger is the orbit radius.$ 39. $Consider the following spectral lines for atomic hydrogen:(A) First line of Paschen series(B) Second line of Balmer series(C) Third line of Paschen series(D) Fourth line of Bracket series. The correct arrangement of the above lines in ascending order of energy is:$ (1) $(D) < (C) < (A) < (B)$ (2) $(D) < (A) < (C) < (B)$ (3) $(C) < (D) < (B) < (A)$ (4) $(A) < (B) < (C) < (D)$ 40. $Which of the following sets of quantum numbers is not allowed ?$ (1) $n = 3,l = 2,mi=0,s = + \frac{1}{2}$ (2) $n = 3,l = 2,m, = -2,s = + \frac{1}{2}$ (3) $n = 3,l = 3, m_{1} =-3,s = - \frac{1}{2}$ (4) $n = 3,l = 0, m_{1} =0, s = - \frac{1}{2}$ 41. $The calculated spin-only magnetic moments of K_{3} (Fe (OH)_{6}) and K_{4} (Fe (OH)_{6}) respectively are:$ (1) $3.87 and 4.90 B.M.$ (2) $4.90 and 5.92 B.M.$ (3) $4.90 and 4.90 B.M.$ (4) $5.92 and 4.90 B.M.$ 42. $Which of the following corresponds to the energy of the possible excited state of hydrogen?$ (1) $- 13.6 eV$ (2) $13.6 eV$ (3) $- 3.4 eV$ (4) $3.4 eV$ 43. $Match the following species with the correct number of electrons present in them. Species Number of electrons A. Be^{2 +} (i) 0 B. H^{+} (ii) 10 C. Na^{+} (iii) 2 D. Mg^{+} (iv) 11 (v) 4 Codes A B C D$ (1) $(iv) (iii) (ii) (i)$ (2) $(i) (ii) (iii) (iv)$ (3) $(v) (iv) (i) (iii)$ (4) $(iii) (i) (ii) (iv)$ 44. $The energy of second Bohr orbit of the hydrogen atom is - 328 k J m o 1^{- 1}; hence the energy of fourth Bohr orbit would be$ (1) $- 41 k J m o 1^{- 1}$ (2) $- 82 k J m o 1^{- 1}$ (3) $- 164 k J m o 1^{- 1}$ (4) $- 1312 k J m o 1^{- 1}$ 45. $The correct set of four quantum numbers for the outermost electron of sodium (Z = 11) is$ (1) $3, 1, 0, 1/2$ (2) $3, 1, 1, 1/2$ (3) $3, 2, 1, 1/2$ (4) $3, 0, 0, 1/2$ 46. $If the uncertainty in velocity is \frac{1}{2 m} \frac{h}{π}, then the ratio of uncertainty in position and momentum is$ (1) $10 : 1$ (2) $100 : 1$ (3) $1 : 1$ (4) $0.5 : 1$ 47. $A body of mass 10 mg is moving with a velocity of 100 m s^{- 1} . The wavelength of de Broglie wave associated with it would be (h = 6.63 \times 10^{- 34} Js)$ (1) $6.63 \times 10^{- 35} m$ (2) $6.63 \times 10^{- 34} m$ (3) $6.63 \times 10^{- 31} m$ (4) $6.63 \times 10^{- 37} m .$ 48. $Based on the equation: ΔE = 2.0 \times 10-18 J (\frac{1}{n _{2}^{2}} - \frac{1}{n _{1}^{2}}) the wavelength of the light that must be absorbed to excite hydrogen electron from level n = 1 to level n = 2 will be: (h = 6.625 \times 10-34 Js, C = 3 \times 108 ms^{-1})$ (1) $1.325 \times 1 0^{-7} m$ (2) $1.325 \times 1 0^{-10} m$ (3) $2.650 \times 1 0^{-7} m$ (4) $5.300 \times 1 0^{-10} m$ 49. $With regard to photoelectric effect, identify the correct statement among the following.$ (1) $Number of e^{-} ejected increases with the increase in the frequency of incident light.$ (2) $Number of e^{-} ejected increases with the increase in work function.$ (3) $Number of e^{-} ejected increases with the increase in the intensity of incident light.$ (4) $Energy of e^{-} ejected increases with the increase in the intensity of incident light.$ 50. $The number of radial nodes present in 3 p orbital is$ (1) $0$ (2) $1$ (3) $2$ (4) $3$ 51. $Work function (W_{o}) values of six metals (in (eV) are given below: Li Mg Cu Ag K Na 2.42 3.7 4.8 4.3 2.25 2.3 How many of the above metals do not eject the electrons when they are made to strike with radiation of wavelength 400 nm ? (H = 6.62 \times 10^{- 34} Js)$ (1) $4$ (2) $2$ (3) $3$ (4) $5$ 52. $Mg^{2 +} is isoelectronic with$ (1) $Cu^{2 +}$ (2) $Zn^{2 +}$ (3) $Na^{+}$ (4) $Ca^{2 +}$ 53. $Which one of the following sets of ions represents the collection of isoelectronic species?$ (1) $K^{+}, Cl^{-}, Mg^{2 +}, Sc^{3 +}$ (2) $Na^{+}, Ca^{2 +}, Sc^{3 +}, F^{-}$ (3) $K^{+}, Ca^{2 +}, Sc^{3 +}, Cl^{-}$ (4) $Na^{+}, Mg^{2 +}, Al^{3 +}, Cl^{-}$ 54. $For any given series of spectral lines of atomic hydrogen, let ∆ v = v_{max} fl v_{min} be the difference in maximum and minimum frequencies in c m^{- 1} . The ratio of ∆ v_{Lyman} / ∆ v_{Balmer} is:$ (1) $4:1$ (2) $9:4$ (3) $5:4$ (4) $27:5$ 55. $The speed of the electron (in ms^{- 1}) in the third orbit of hydrogen atom is approximately (mass of electron = 9.1 \times 10^{- 31} kg)$ (1) $3.6 \times 10^{5}$ (2) $2.18 \times 10^{6}$ (3) $7.26 \times 10^{5}$ (4) $2.18 \times 10^{5}$ 56. $The value of Rydberg constant (R_{H}) is 2.18 \times 10^{- 18} J . The velocity of electron having mass 9.1 \times 10^{- 31} kg in Bohr's first orbit of hydrogen atom =____\times 10^{5} ms^{- 1} (nearest integer).$ 57. $The maximum number of electrons that can have principal quantum number, n = 3, and spin quantum number, m_{s} = -1/2, is$ 58. $The number of photons emitted by a monochromatic (single frequency) infrared range finder of power 1 m W and wavelength of 1000 nm, in 0.1 second is x \times 1 0^{13} . The value of x is ____. (Nearest integer) (h = 6.63 \times 1 0^{- 34} Js, c = 3.00 \times 1 0^{8} m s^{- 1})$ 59. $Consider the following set of quantum numbers n 1 m_{1} A. 3 3 -3 B 3 2 -2 C 2 1 +1 D. 2 2 +2 The number of correct sets of quantum numbers is _______$ 60. $The energy of an electron in the first Bohr orbit of the H -atom is -13.6 eV. The magnitude of energy value of an electron in the first excited state of Be^{3 +} is eV (nearest integer value).$