Atomic Structure PYQs Set 12 (PDF)

Set 12 of 14 · Questions 331-360 of 415

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Mere Teacher · Previous Year Questions JEE Main Chemistry · Atomic Structure · Set 12 (Q331-360)
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331. $Which one of the following about an electron occupying the 1 s orbital in a hydrogen atom is incorrect? (Bohr's radius is represented by a_{0})$ (1) $The probability density of finding the electron is maximum at the nucleus$ (2) $The total energy of the electron is maximum when it is at a distance a_{0} from the nucleus$ (3) $The electron can be found at a distance 2 a_{0} from the nucleus$ (4) $The 1 s orbital is spherically symmetrical$ 332. $What will be the longest wavelength line in Balmer series of spectrum?$ (1) $546 nm$ (2) $656 nm$ (3) $566 nm$ (4) $556 nm$ 333. $Which of the following set a of quantum numbers is correct for an electron in 4f orbital?$ (1) $n = 4, l =3, m = +4, s = +1/2$ (2) $n = 4, l = 4, m = -4, s = -1/2$ (3) $n = 4, l = 3, m = +1, s = +1/2$ (4) $n = 3, l=2, m =-2, s = +1/2$ 334. $The de Broglie wavelength (λ) associated with a photoelectron varies with the frequency (v) of the incident radiation as, [v_{0} is threshold frequency] :$ (1) $λ \frac{1}{( v - v _{0} ) ^{\frac{3}{2}}}$ (2) $λ \frac{1}{( v _{0} - v _{0} )}$ (3) $λ \frac{1}{( v - v _{0} ) ^{\frac{1}{2}}}$ (4) $λ \frac{1}{( v - v _{0} ) ^{\frac{1}{4}}}$ 335. $In hydrogen atom, energy of first excited state is - 3.4 e V . Then find out K.E. of same orbit of hydrogen atom$ (1) $+ 3.4 e V$ (2) $+ 6.8 e V$ (3) $- 13.6 e V$ (4) $+ 13.6 e V$ 336. $A 0.66 kg ball is moving with a speed of 100 m / s . The associated wavelength will be (h = 6.6 \times 1 0^{- 34} J s)$ (1) $6.6 \times 1 0^{- 32} m$ (2) $6.6 \times 1 0^{- 34} m$ (3) $1.0 \times 1 0^{- 35} m$ (4) $1.0 \times 1 0^{- 32} m$ 337. $Consider the following complex ions P = (FeF_{6})^{3 -} Q = (V (H_{2} O)_{6})^{2 +} R = (Fe (H_{2} O)_{6})^{2 +} The correct order of the complex ions, according to their spin only magnetic moment values (in B.M.) is :$ (1) $R < Q < P$ (2) $R < P < Q$ (3) $Q < R < P$ (4) $Q < P < R$ 338. $The electrons are more likely to be found :$ (1) $in the region a and c$ (2) $in the region a and b$ (3) $only in the region a$ (4) $only in the region c$ 339. $According to the Bohr theory, which of the following transitions in the hydrogen atom will give rise to the least energetic photon?$ (1) $n = 6 to n = 1$ (2) $n = 5 to n = 4$ (3) $n = 6 to n = 5$ (4) $n = 5 to n = 3$ 340. $The radius of hydrogen atom in the ground state is 0.53 Å. The radius o f L i^{2 +} ion (atomic number = 3) in a similar state is$ (1) $0.53 Å$ (2) $1.06 Å$ (3) $0.17 Å$ (4) $0.265 Å$ 341. $In a Bohr’s model of an atom, when an electron jumps from n = 1 to n = 3, how much energy will be emitted or absorbed?$ (1) $2. 389 \times 1 0^{- 12} ergs$ (2) $0. 239 \times 1 0^{- 10} ergs$ (3) $2. 15 \times 1 0^{- 11} ergs$ (4) $0. 1936 \times 1 0^{- 10} ergs$ 342. $Identify the incorrect statements from the following.$ (1) $The shapes of d_{xy}, d_{yz}, and d_{zx} orbitals are similar to each other; and d_{x^{2} - y^{2}} and d_{z^{2}} are similar to each other.$ (2) $All the five 5d orbitals are different in size when compared to the respective 4 d orbitals.$ (3) $All the five 4d orbitals have shapes similar to the respective 3 d orbitals.$ (4) $In an atom, all the five 3d orbitals are equal in energy in free state.$ 343. $Consider the following sets of quantum numbers: n l m s (i) 3 00 + 1/2 (ii) 2 2 1 + 1/2 (iii) 4 3 - 2 - 1/2 (iv) 1 0 - 1 - 1/2 (v) 3 2 3 + 1/2 Which of the following sets of quantum number is not possible?$ (1) $(i), (ii), (iii) and (iv)$ (2) $(ii), (iv) and (v)$ (3) $(i) and (iii)$ (4) $(ii), (iii) and (iv)$ 344. $Consider the hypothetical situation where the azimuthal quantum number, l, takes values 0, 1, 2, \dots, n + 1, where n is the principal quantum number. Then, the element with atomic number$ (1) $9 is the first alkali metal$ (2) $6 has a 2 p -valence subshell$ (3) $8 is the first noble gas$ (4) $13 has a half-filled valence subshell$ 345. $According to law of photochemical equivalence the energy absorbed (in ergs/mole) is given as (h = 6.62 \times 1 0^{- 27} ergs, c = 3 \times 1 0^{10} cm s^{- 1}, N_{A} = 6.02 \times 1 0^{23} mo l^{- 1})$ (1) $\frac{1.196 \times 1 0 ^{8}}{λ}$ (2) $\frac{2.859 \times 1 0 ^{5}}{λ}$ (3) $\frac{2.859 \times 1 0 ^{16}}{λ}$ (4) $\frac{1.196 \times 1 0 ^{16}}{λ}$ 346. $The velocity (v) of de Broglie wave is given by [ν = Frequency, m = mass, C = Velocity of light]$ (1) $m C^{2}$ (2) $ν λ$ (3) $\frac{h ν}{m C}$ (4) $\frac{C ^{2}}{ν}$ 347. $Given below are the quantum numbers for 4 electrons. A. n = 3, l = 2, m_{l} = 1, m_{s} = +1/2 B. n = 4, l = 1, m_{l} = 0, m_{s} = +1/2 C. n = 4, l = 2, m_{l} = -2, m_{s} = -1/2 D. n = 3, l = 1, m_{l} = -1, m_{s} = +1/2 The correct order of increasing energy is :$ (1) $D<B<A<C$ (2) $D<A<B<C$ (3) $B<D<A<C$ (4) $B<D<C<A$ 348. $Given below are two statement: Statement (I): It is impossible to specify simultaneously with arbitrary precision, both the linear momentum and the position of a particle. Statement (II): If the uncertainty in the measurement of position and uncertainty in measurement of momentum are equal for an electron, then the uncertainty in the measurement of velocity is ⩾ \frac{h}{π} \times \frac{1}{2 m} . choose the correct answer from the options given below:$ (1) $Statement I is false but Statement II is true$ (2) $Both Statement I and Statement II are false$ (3) $Both Statement I and Statement II are true$ (4) $Statement I is true but Statement II is false$ 349. $The radiation with maximum frequency is$ (1) $X-rays$ (2) $radio waves$ (3) $UV rays$ (4) $IR rays$ 350. $Match List I with List II List - I (Element) A. N B. S C. Br D. Kr List - II (Electronic configuration) I . [Ar] 3 d^{10} 4 s^{2} 4 p^{5} AR II . [Ne] 3 s^{2} 3 p^{4} III . [He] 2 s^{2} 2 p^{3} IV . [Ar] 3 d^{10} 4 s^{2} 4 p^{6} Choose the correct answer from the options given below:$ (1) $A-III, B-II, C-I, D-IV$ (2) $A-II, B-I, C-IV, D-III$ (3) $A-I, B-IV, C-III, D-II$ (4) $A-IV, B-III, C-II, D-I$ 351. $Which one is the wrong statement?$ (1) $The uncertainty principle is ∆ E \times ∆ t \geq \frac{h}{4 π}$ (2) $Half-filled and fully filled orbitals have greater stability due to greater exchange energy, greater symmetry and more balanced arrangement.$ (3) $The energy of 2 s ‐orbital is less than the energy of 2 p ‐orbital in case of hydrogen like atoms.$ (4) $de‐Broglie’s wavelength is given by λ = \frac{h}{m v}, where m = mass of the particle, v = group velocity of the particle$ 352. $The orbital angular momentum of an electron in 3 s orbital is \frac{x h}{2 π} . The value of x is (nearest integer)$ 353. $The work function (φ) of some metals is listed below. The number of metals which will show photoelectric effect when light of 300 nm wavelength falls on the metal is$ 354. $Two positively charged particles m_{1} and m_{2} have been accelerated across the same potential difference of 200 keV as shown below. [Given mass of m_{1} = 1 amu and m_{2} = 4 amu] The deBroglie wavelength of m_{1} will be x times of m_{2} . The value of x is____(nearest integer)$ 355. $Ge(Z = 32) in its ground state electronic configuration has x completely filled orbitals with m_{l} =0. Thevalue of x is ____.$ 356. $When light of wavelength 248 nm falls on a metal of threshold energy 3.0 eV, the de-Broglie wavelength of emitted electrons is ∖ AA . (Round off to the Nearest Integer). & [Use : 3 = 1.73, h = 6.63 \times 10^{- 34} J_{S} & m_{e} = 9.1 \times 10^{- 31} kg; c = 3.0 \times 10^{8} ms^{- 1} & (leV = 1.6 \times 10^{- 19} J)$ 357. $A metal surface is exposed to 500nm radiation. The threshold frequency of the metal for photoelectric currentis 4.3 \times 1 0^{14} Hz. The velocity of ejected electron is ____ \times 1 0^{5} m s^{- 1} (Nearest integer) [Use :h = 6.63 \times 1 0^{- 34} Js, m_{e} = 9.0 \times 1 0^{- 31} kg]$ 358. $Electromagnetic radiation of wavelength 663 nm is just sufficient to ionize the atom of metal A. The ionization energy of metal A in kJ m o l^{- 1} is ____. (Rounded off to the nearest integer) (h = 6.63 \times 1 0^{- 34} J s, c = 3.00 \times 1 0^{8} m s^{- 1}, N_{A} = 6.02 \times 1 0^{23} m o l^{- 1})$ 359. $Based on Heisenberg's uncertainty principle, the uncertainty in the velocity of the electron to be found within an atomic nucleus of diameter 1 0^{- 15} m is _____\times 1 0^{9} m s^{- 1} (nearest integer) [Given : mass of electron = 9.1 \times 1 0^{- 31} kg, Plank's constant (h) = 6.626 \times 1 0^{- 34} Js] (Value of π = 3.14)$ 360. $Electrons in a cathode ray tube have been emitted with a velocity of 1000 m s^{- 1} . The number of following statements which is/are true about the emitted radiation is_________. Given : h = 6 x 1 0^{- 34} Js, m_{e} = 9 x 1 0^{- 31} kg. (A) The deBroglie wavelength of the electron emitted is 666.67nm. (B) The characteristic of electrons emitted depend upon the material of the electrodes of the cathode ray tube. (C) The cathode rays start from cathode and move towards anode. (D) The nature of the emitted electrons depends on the nature of the gas present in cathode ray tube.$