Tiêu đề DPP-6 SOLUTION.pdf ✅

CLASS : XIth SUBJECT : CHEMISTRY DATE : DPP No. : 6 1 (a) E = 3 × 10―12ergs λ = ? h = 6.62 × 10―27ergs c = 3 × 1010cms ―1 E = hc λ 3 × 10―2 = 6.62 × 10―27 × 3 × 1010 λ λ = 6.62 × 10―27 × 3 × 1010 3 × 10―12 = 6.62 × 10―5 cm = 662 × 10―7 cm = 662 × 10―9m = 662 nm. 3 (a) 1. 1s 2. 2s 3. 2p 4. 3d 5. 3d In the absence of any field, 3d in (D) and (E) will be of equal energy. 3 (c) Zeeman effect is splitting up of the lines of an emission spectrum in a magnetic field. 4 (d) Bohr radius for nth orbit = 0.53 × n 2 Z Where, Z = atomic number Topic :- STRUCTURE OF ATOM Solutions
∴ Bohr radius of 2nd orbit of Be 3+ = 0.53 × (2) 3 4 = 0.53 Å (d) Bohr radius of 1st orbit of H = 0.53 × (1) 2 1 Hence, Bohr’s radius of 2nd orbit of Be 3+ is equal to that of first orbit of hydrogen. 5 (c) λ = h mv ∴ mv = 6.626 × 10―34 5200 × 10―10 = 1.274 × 10―27 For electron, m = 9.1 × 10―31kg 9.1 × 10―31 × v = 1.274 × 10―27 v = 1400 m/s 6 (b) (n + l) is more for a subshell, more will be its energy. 7 (c) [Ar]3d 10,4s 1 (atomic no. 29) electronic configuration belongs to copper. 8 (a) Li+ has charge of 1 proton due to loss of electron. 9 (c) Mass or proton = 1.672614 × 1027kg Mass of electron = 1.60211 × 10―31kg ∴ Mass of proton/Mass of electron = 1 1837 10 (c) Follow :En = E1/n 2 12 (a) Orbital angular momentum = l(l + 1) × h 2π For p-electron (l = 1) = 1(1 + 1) × h 2π = 2 × h 2π = h 2π 13 (a) Transition from any higher level to n = 1 gives Lyman series. 14 (a) Total energy = ― e 2 2rn = ―3.4 eV = E1 n 2 ∴ n 2 = ―13.6 ―3.4 = 4 ∴ n = 2 The velocity in II orbit = u1 2 = 2.18 × 108 2 cm sec―1
∴ λ = h mu = 6.6 × 10―27 × 2 9.108 × 10―28 × 2.18 × 108 = 6.6 × 10―10 15 (c) The orbital dz 2 has 2 lobes. 16 (c) Nucleus of an atom is small in size but carries the entire mass i.e., contains all the neutrons and protons. 17 (a) In C2H2 total electrons = 6 + 6 + 1 + 1 = 14. 18 (a) Cu+ has 3d 10 configuration. 19 (a) Only 2 electrons in p-orbitals can have m = 0.
ANSWER-KEY Q. 1 2 3 4 5 6 7 8 9 10 A. A A C D C B C A C C Q. 11 12 13 14 15 16 17 18 19 20 A. C A A A C C A A A C