Class 11 chemistry atomic structure exercise, Exercises of Chemistry

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1 6, Atomic Models and Dual Nature of Electromagnetic Radiation Ifthe wavelength for an clectron emitted from H-atom is 3.3 x 107!° m, then energy absorbed by the electron in its ground state compared to minimum energy required for its escape from the atom, is times, (Nearest integer) (NY, July 28, 2022 (ID] [Given : h= 6,626 x 104 Js} “Mass of electron = 9.1 x 1073! kg Consider an imaginary ion 3§x’-, The nucleus contains *a’% more neutrons than the number of electrons in the ion. The value of ‘a’ is___. [nearest integer] INV, July 26, 2022 (11) Ifthe work function ofa metal is 6.63 x 10°!? J, the maximum wavelength of the photon required to remove a photoelectron from the metal is nm. (Nearest integer) [Given: h=6.63 x 10 Js, andc=3 x 108ms7] - INV, June 28, 2022 (1)] Hydrogen has three isotopes ; protium (!H), deuterium (Hor D) and tritium @H or T). They have nearly same chemical properties but different physical properties. They differ in [June 28, 2022 (11)] (2) number of protons : (b) atomic number (©) electronic configuration (d) atomic mass The minimum energy that must be possessed by photons in order to produce the photoelectric effect with platinum metal is: [Given; The threshold frequency of platinum is 1.3% 10" sland h=6.6* 10-4 Js.) [June 25, 2022 (11)] (a) 3.21 «10 (b) 6.24* 10!) () 8.58% 10°97 (d) 9:76 = 1075 A 50 watt bulb emits monochromatic red light of wavelength of795 nm. The number of photons emitted per second by the bulb is x * 10?, The value of x is . [Given :h= 6.63 x 1074 Jsand ¢ = 3.0 * 10ms"!] INV, Sep. 1, 2021] The number of photons emitted by a monochromatic _ (single frequency) infrared range finder of power 1 mW 10. * Which of the following forms ofhydrogen and wavelength of 1000 nm, in 0.1 second isx = 103. The value of x is . (Nearest integer) (A= 6.63 * 10° Js, c= 3.00 * 10% ms~!) INV. Aug. 27, 2021 (ID] A metal surface is exposed to 500 nm radiation. The threshold frequency of the metal for phowlectric current is 4.3 x 10'4 Hz. The velocity of ejected electron is x 10°ms~! (Nearest integer) [Use: = 6.63 x 10-4 Js, m,=9.0 x 107! kg] INV, Aug. 26, 2021 (11)] If the Thomson model of the atom was correct, then the result of Rutherford’s gold foil experiment would have been : [July 27, 2021 (ID| (a) All of the a-particles pass through the gold foil without decrease in speed. (b) a-Particles are deflected over a wide range of angles. (c) All c-particles get bounced back by 180°. (d) o-Particles pass through the gold foil deflected by small angles and with reduced speed. A source of monochromatic radiation of wavelength 400 nm provides 1000 J of energy in 10 seconds. When this radiation falls on the surface of sodium, x * 10°? electrons are ejected per second, Assume that wavelength 400 nmis sufficient for ejection of electron from the surface of sodium metal. The value ofxis___. (Nearest integer) (i= 6.626 * 1043s) INY, > particles? (a) Proton Ht [Feb, 26, 2021 (ID) (b) Tritium 7H (©) Protium fH (@) Deuterium ? H Electromagnetic radiation of wavelength 663 nm is just sufficient (0 ionise the atom of metal A, The ionization energy of metal Ain kJmol!is___. (Rounded-off'to the nearest integer) [A = 6.63 = 10° Js, ¢ = 3.00 10% ms-1, Ny = 6.02 * 108 mol"4) INV, Feb, 25, 2021 1D] ‘The work function of sodium metal is 4.41 x 10°? J. Uf photons of wavelength 300 ni are incident on the metal, the kinetic energy of the ejected electrons will be (h= 6.63 x 104 Js;¢=3 * 108 avs) «107, INV, Sep. 02, 2020 (ID] a6 Ifpisthe momentum ofthe fastest clectron ejected from a metal surface after the irradiation of light having wavelength A, then-for 1,5p momentum of the photoelectron, the wavelength of the light should be: (Assume kinetic energy of ejected photoelectron to be very high in comparison to work function): [April 8, 2019 ID] 1 2 4 @ 3a ® ss © x Wo What is the work function of the metal if the light of wavelength 4000 A generates photoclectrons of velocity 6x10° ms" fromit? [Jan 12, 2019 (1)] (Mass of electron=9* 10! kg Velocity of light = 3x108ms"! Planck's constant=6.626%10-4 Js Charge of electron =1.6x10"JeV"') (@ 09eV (b) B1cV (©) 21eV (d) 40eV 16. ‘A stream of electrons from a heated filament was passed between two charged plates keptat a potential difference V volt. If'e''and m are charge and mass of an electron, respectively, then the value of A/A (where \ is wavelength associated with electron wave) is given by: [2016] @) JmeV (>) J2meV (c) meV (a) 2mev 17. If, and 2. be threshold wavelength and wavelength of incident light, the velocity of photoelectron ejected from the metal surface is: {Online April 11, 2014] @) f200-2) FE Go-a) ahe( my -2-) nf) 1 © Wn (9% ® Vinlie d 18. The energy required to break one mole of Cl — Cl bonds in Cl, is 242 kJ mol"!. Thelongést wavelength of light capable of breaking a single Cl—Cl bond is (c=3 x 108 ms” and N, = 6.02 x 10% mal-!), (2010) (a) 594nm (b) 640nm (c) 700nm = (d) 494nm 19, Calculate the wavelength (in nanometer) associated with a proton moving at 1.0 « 103ms~!, (Mass of proton = 1,67 * 1077 kg and h= 6.63 x 10-4 Js) 12009} (@) 040nm (6) 25nm = (c) 14.0nm (d) 032nm Bohr’s Model for Hydrogen Atom | (Emission and Absorption Spectra) 20. Identify the incorrect statement from the following. : [July 28, 2022 ()] (@) A circular path around the nucleus in which an clectron moves is proposed as Bohr’s orbit. (b) An orbital is the one electron wave function (y)inan atom, (c) The existenc if its i hydrones ee 's orbits is supported by (@) Atomic orbital is character ' erised by the qua numbers n and f only vegan 22. 23. 24, 25, 26, . xx 108 m, The valucofx is BcHeMistaye | Given below are two statements, One is labelled ag Asserdon A and the other is labelled as Reason Rt Assertion A: Energy of 2s orbital of hydrogen atom js greater than that of 2s orbital of lithium. Reason R : Energies of the orbitals in the same subshel| decrease with increase in the atomic number, In the light of the above statements, choose the currec answer from the options given below, ‘ [uly 27, 2022 (1)} (a) Both Aand R are truc and Ris the correct explanation ofA. (b) Both A and R are true but R is NOT the cortect explanation ofA. ° (©) Ais truce but R is false. (d) Ais false but Ris true, ‘ When the excited electron ofa Hatom from n= 5 drops to the ground state, the maximum number of emission lines observed are INV, July 25, 2022 (11)} If the radius of the 3rd Bohr's orbit of hydrogen atom is r; and the radius of 4" Bohr's orbit is r,. Then: [June 26, 2022 (1) 16 @) n= 0) 4=O4 4 © natn @natn The longest wavelength of light that can be used for the ionisation of lithium atom (Li) in its ground state is (Nearest Integer) (Given ; Energy of the electron in the first shell of the hydrogen atom is 2,2 x 10718 J;h= 6.63 x 107 Js and c=3x 108 ms") INV. dune 25, 2022 (| The kinetic energy ofan electron in thesecond Bohr orbit 2 U ;, > is of'a hydrogen atom is equal to anal 2 The value of 10x Cagis radius of Bohr's orbit) (Nearest integer) [Given : =3.14] INV, Aug. 27, 2021 (1 Given below are two statements, Stutement 1; According to Bohr’s model of an atom, qualitatively the magnitude of velocity of electron increases with decrease in positive charges on the nucleus as there is no strong hold on the electron by the nucleus. Statement 11: According to Bohr's model of an atom, qualitatively the magnitude of velocity of electron increases with decrease in principal quantum number. In the light of the above statements, chante te most i i gi clow appropriate answer from the options How anil {a) Both Statement I and Statement Il are false (b) Both Statement I and Statement II are true (c) Statement 1 is false but Statement Ill is true (d) Statement I is true but Statement I is false 38. The ground state energy of hydrogen atom is —13.6 eV. 40. 4. 42. 43. 44. 46. The energy of second excited state of Het ion in eV is: [Jan, 10, 2019 (11), Similar 2002] (a) 54.4 (b) -3.4 (©) -6.04 — (d) —27.2 For emission line ofatomic hydrogen from 1,= 8 to 1,=1, the ome ji ae plot of wave number (7 ) against (5) will be (The Rydberg, consiant, Ry, isin wave number unit) (a) Linear with intercept - Rj, (b) Non linear . (c) Linear with slope Ry (d) Linear with slope—R,, . Which of the following statements is false’ : [Online April 16,2018] (a) Splitting of spectral lines in electrical field is called Stark effect : (b) Frequency ofemitted radiation from a black body goes froma lower wavelength to higher wavelength as the temperature increases 3 . (c) Photon has momentum as well as wavelength (d) Rydberg constant has unit of energy Ejection of the photoelectron from metal in the photoelectric effect experiment can be stopped by applying 0.5V when the radiation of 250 nm is used. The work function of the metal is : . [Online April 15, 2018 (1)] (a) 4eV 0b) 5SeEV. (©) 45eV.—) SEV The electron in the hydrogen atom undergoes transition from higher orbitals to orbital of radius 211.6 pm. This transition is associated with: — |Online April 9, 2017] (a) Lymanseries + (b) Balmer series (c) Paschen series (d) Brackettseries Which of the following is the energy of a possible excited state of hydrogen ? . [2015] (a) -34eV (b) +68eV (©) +13.6eV (d) -68eV [Jan.9, 2019 (1) The energy ofan electron in first Bohr orbit of H-atom is— 13.6 eV, The energy value of electron in the excited state of Li** is: [Online April 9, 2014; Similar 2010] (a) -27.2¢V (b) 30.6cV (c) -30.6eV @) 27.2eV na ne the wavelength of the light that must be absorbed to excite hydrogen electron from level = 1 to level n=2 will be: (= 6.625 x 10 Js,e=3 x 108 ms“) [Online April 11, 2014, (a) 1.325% 107m (b) 1.325* 10-"’m (©) 2.650* 107m (d) 5.300* 10-!?m ifm ande are the mass and charge of the: revolving electron in the orbit of radius r for hydrogen atom, the total energy ofthe revolving electron will be: [Online April 12, 2014) 2 2 2 a Lf e 2 le @ 5 ran) -- © “ ww as Based on the equation: AF = -2.0x wa] ilar 2013) 47. 48, 49, 50. $1. 52. 54. $5. 1 — Excited hydrogen atom emits light in the ultraviolet Tepi at 2.47 * 10'S Hz. With this frequency, the energy single photon is: i i ‘ he Gea ion) [Online April 12, 2014 (@) 8.041 1075 (b) 2.680 10-195 (c) 1.640 10-185 (d) 6.111 x 10-177 Ionization energy of gaseous Na atoms is 495.5 kJ mot! The lowest possible frequency of light that ionizes , sodium atom is [Online April 19, 2014) (i= 6,626 x 10 Js, N, = 6.022 x 10” mol") (a) 7.50x 104s (b) 4.76 10!4¥s-1 (6) 3.15 105s (@) 1.24% 105s The wave number of the first emission line in the Balmer series of H-spectrum is: [Online April 22, 2013} (R= Rydberg constant): 5 9 7 35: —R <= eA = @ 36 (b) 700 Rk © m7 R @ mI R The limiting line in Balmer series will havea frequencyof . [Online May 7, 2012] (Rydberg constant, R,, = 3.29 10" cycles/s) @) 8.22 10! st (b) 3.29 105s"! ” (oc) 3.65 x 10" st (d) 5.26% 10%s7 The frequency of light emitted for the transition n=4 ton = 2 of the He* is equal to the transition in H atom corresponding to which of the following ? [2011 RS] (a) n=2ton=1 (b) n=3ton=2 (c) n=4ton=3 (d) 2=3ton=1 The ionization enthalpy of hydrogen atom is 1.312 x 10°) ‘mol-!. The energy required to excite the electron in the atom from n= | ton=2is (a) 8.51 x 10°Jmol" (b) 6.56% 10°Jmol" (c) 7.56x 105Jmot!’ — (d)_:9.84x 10° Jmol"! According to Bohr's theory, the angular momentum of an [2008] electron in 5" orbit is [2006] a) 10h/x (b) 25h/n (© 25h/n @ 1L0h/x . The wavelength of the radiation emitted, when ina hydrogen atom electron falls from infinity to stationary state 1, would be (Rydberg constant = 1.097% 107 m=") (a) 406nm (b) 192nm [2004] (c) 91nm * @) 9.1%10%nm . In Bohr series of lines of hydrogen spectrum, the third line from the red end corresponds to which one of the following inter-orbit jumps of the electron for Bohr orbits in anatom of hydrogen ' [2003] @) 5-72 () 2-5 () 41 (d) 332 Dual Behaviour of Matter and | Heisenberg Uncertainty Principle , 56. lectron in an The minimum uncertainty in the speed ofan el me one-dimensional region of length 2ay (Where a radius 52.9 pm) is kms. (Given ; Mass of electron = 9.1* 10-3 kg, Planck's constant h=6.63 x 10 Js) [NY, July 29, 2022 (01 Structure offAtom) im 57. The wavelength of an electron and a neutron will become 58. 59. 60. + 61. 62. 63. 64, 68, equal when the velocity of the electron is x times the’ ~ velocity of neutron. The value of.x is « (Nearest Integer) (Mass of electron is 9.1 x 10-3! kg and mass of neutron is 1.6 * 10-27 kg) INV, July 26, 2022 (D] If the uncertainty in velocity and position of a minute particle in space are, 2.4 = 10°26 (ms-!) and 10-7 (im) respectively. The mass of the particle in.g is (Nearest integer) (Given : h = 6,626 x 1074 Js) [NV, June 27, 2022 (1)} The energy of one mole of photons of radiation of wavelength 300 nm is (Given : h= 6.63 x 10™ Js,N,=6,02 * 10% mol", c=3% 108 ms!) [June 24, 2022 (11) (a) 235k mol! (b) 325k) mol-! (c) 399k) mol! (a) 435k) mol"! An accelerated electron has speed of 5 x 10° ms~! with an uncertainty of 0.02%. The uncertainty in finding its location while in motion is x * 10m. The value of x js ; (Nearest integer) [Use mass of electron = 9.1 « 1073! kg, h=6.63 x 10°*Js,7=3.14) INV, July 25, 2021 (ED). The wavelength of electrons accelerated from rest through a potential difference of 40 kV isx* 10°! m. The value of xis « (Nearest integer) ‘ Given : Mass ofelectron = 9.1 = 107! kg Charge on an electron = 1.6 « 10-!9C Planck’s constant = 6.63 x 10-4 Js[NV, July 20, 2021 (11)} When light of wavelength 248 nm fallson a metal of threshold energy 3.0 eV, the de-Broglie wavelength of emitted electrons is____ A. (Round off to the Nearest Integer). (Use: J3 =1.73,n = 6.63x107*4 Js, ‘me = 9,1%107* kg;¢= 3.0x10%ms7!;1 eV = 1.6x107!95) INV, Mareh 16, 2021 (1)] Aball weighing 10 g is moving witha velocity of 90 ms-!, Ifthe uncertainty in its velocity is 5%, then the uncertainty in its position is * 1073 m, (Rounded off to the nearest integer) . [Given :h=6,63 x 10-4 Js) INV, Feb, 26, 2021 (I) A proton and a Li?* nucleus are accelerated by the same potential. If, ,and A, denote the de Broglie wavelengths d, of Li and proton respectively, then the valuc of rm ** 107. The value of x is INV, Feb. 24, 2021 (I)] (Rounded off to the nearest integer) (Mass of Li?*= 8/3 times mass of proton) The figure that isnot adirect manifestation of the quantum nature of atoms is ; [Sep, 02, 2020 (1)) is A-A1 Th? 7, Intensity ue (a) of black body radiation Ty Wavelength Rb K Na (0) photoelectrons © Kinetic energy of Frequency of incident radiation —> Increasing wavelength say thanks to me on telegram @Aakash8057 Absorption spectrum Internal (d) energy of wee Ar (c) 300 400 500 600 ‘Temperature (K) The de Broglie wavelength of an electron in the 4 Bohr orbit is: [Jan. 09, 2020(1D] (a) 2na, (b) 4za, (©) 6na, (d) 8za, If the de Broglie wavelength of the electron in n Bohr orbit in a hydrogenic atom is equal to 1.5 mag (a, is Bohr radius), then the value of /Z is: Jan. 12, 2019 (ID] (a) 0.40 (b) 1.50 (c) 1.0 (d) 0.75 The de Broglie wavelength (A) associated with a photoelectron varies with the frequency (v) of the incident radiation as, (vy is threshold frequency): Wan, 11,2019 ID] \ QQ) A= ——- @ Ae Ginvo) (V=vo)i 1 ( As 7 (d) 4x ——_ (V=Vo)2 (V=vo)2 The de-Broglic's wavelength of electron present in first Bohr orbit of 'H' atomis: (a) 4x0529A 0.529 [Online April 15, 2018 (1)] (b) 2nx0529A A (d) 0.529A, 2n Structure of Atom 82, Consider the following set of quantum numbers: no tom -3 -2 +1 . 2 +2 . The number of correct sets of quantum numbers is INV, June 27, 2022 (I1)] - Nw 3 3 2 2 pap> $3. The number of radial and angular nodesin 4d orbital are respectively [June 26, 2022 (11)] (a) land2 (b) 3and2 (©) land0 (d) 2and1 84, Consider the following pairs of electrons (A) (@)1=3,1= 1,m,= Im=+5 . 1 (b)n=3, L=2,m),= Lm=t> ®) (0) = 3,1=2ym,==2m,=—4 (b) n=3,1=2,m,=~1, m5 © (2) n=4,1=2,m,=2,m=+5 (0) n=3,1=2,m,=2,m,=+ 4 2 The pairs of electron present in degenerate orbitals is/are: [June 24, 2022 (D} (@) OnlyA (b) OnlyB (©) OnlyC (a) (B)and(C) 85. The value of magnetic quantum number of the outermost electron of Zn* ion is + INV, Aug. 31, 2021 (I1)) » 86, TheAzimuthal quantum number for the valence electrons of Ga* ion is INV, July 20, 2021 (1)] + (Atomic number of Ga =31) 87, A certain orbital has no angular nodes and two radial nodes, The orbital is {March 18, 2021 (1)| @ %» (b) % (©) 3s (d) 2s 88, A certain orbital has 1 = 4 and m,=—3, The number of Tadial nodes in this orbital is z : (Round offto the Nearest Integer). INV, Mareh 17, 2021 (1)| Thenumber of orbitals with n= 5, m= +2 is ‘ , Round offto the Nearest Integer). [NV, March 16, 2024 (II)] 90, “The orbital having two radial as well as two angular nodes is: [Feb. 26, 2021 ()} @) 3p @) 4d (©) Sd wy 91. Inthe sixth period, the orbitals that are filled are: [Sep. 05, 2020(1)] 89, 92, 93, 94, 95. 97. 9B, A132 (a) 65, 4f, 5d, 6p (b) Gs, Sd, Sf 6p (©) 65, Sf, 6d, Op @) 6s, 6p, 64, 6f The correct statement about probability density (except at infinite distance from nucleus) is : [Sep. 05, 2020 (I1)} (a) Itcan be zero for 1s orbital (b) Itcan be negative for 2p orbital (c) Itcan be zero for 3p orbital (d) It can never be zero for 2s orbital Consider the hypothetical situation where the azimuthal quantum number, /, takes values 0, 1, 2, .....2+1, wheren is the principal quantum number. Then, the element with atomic number : [Sep. 03, 2020 (11)) (@) isthe first alkali metal (b) 13 hasa half-filled valence subshell (c) 8 is the first noble gas (d) 6 hasa 2p-valence subshell The number of subshells associated with n = 4 and m=—2 quantum numbersis: [Sep. 02, 2020 (11)] @ 8 &) 2 (©) 16 (d) 4 The number of orbitals associated with quantum numbers n=S,m,=+ $ is: [Jan. 07, 2020 (1), Similar Online April 9, 2016] @ I (25 © % (d) 15 . Among the following, the energy of 2s orbital is lowest in: (2017 (S); April 12, 2019 (1) @ K () H © Li (d) Na * The electrons are more likely to be found ; {April 12, 2019 (1) (a) intheregionaandc (b) intheregionaandb (c) onlyin the regiona (d) only inthe Tegion c The graph between |y/ and r (radial distance) is shown below. This represents : {April 10,2019(1)] 2) 7 r (b) 2sorbital (d) 2p orbital (a) 3s orbital (©) Isorbital a-14 09. The isoelectronic set of ions is [2003 (S), 2004 (S), 2005 (S), 2006(5), 2008 (S), April 10,2019 (I)] (a) N'>, 0%, F-andNa* (b) N?-, Lit, Mg?* and O* (c) F>,Lit, Na*and Mg” (d) Lit, Nat, 07> and F~ 100. The quantum number of four electrons are given below : L 2=4,1=2, m=-2,m,== 1/2 D, 2=3,/=2,m,=1,m,=+ 1/2 Il, n=4,/=1,m,=0,m,=+ 1/2 NV. 1=3,/=1,m,=1,m,==1/2 \ The correct order of their increasing energies will be: [2007(S), April 8, 2019 (1)| (a) IV