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Test Paper
𝟏
Chemistry Class –11th Time – 𝟏 𝟐 Hour’s
MM – 50
Q.1- The first (∆1H1) and the second (∆1H2) ionization enthalpies (in kJ mol–1) and the (∆egH) electron
gain enthalpy (in kJ mol–1) of a few elements are given below: ❸
Elements ∆H1 ∆H2 ∆egH
I 520 7300 –60
II 419 3051 –48
III 1681 3374 –328
IV 1008 1846 –295
V 2372 5251 + 48
VI 738 1451 –40
Which of the above elements is likely to be:
(a) the least reactive element.
(b) the most reactive metal.
(c) the most reactive non-metal.
(d) the least reactive non-metal.
(e) the metal which can form a stable binary halide of the formula MX2(X=halogen).
(f) the metal which can form a predominantly stable covalent halide of the formula MX(X=halogen)?
Q.2- How would you explain the fact that the first ionization enthalpy of sodium is lower than that of
magnesium but its second ionization enthalpy is higher than that of magnesium ? ❸
Q.3- What is the basic difference between the terms electron gain enthalpy and electronegativity ? ❸
Q.4- Explain, giving reasons, which of the following sets of quantum numbers are not possible. ❸
(a) n = 2, l = 0, m1 = 0, ms = + ½
(b) n = 1, l = 1, m1 = 0, ms = – ½
(c) n = 3, l = 1, m1 = 0, ms = + ½
(d) n = 2, l = 3, m1 = 0, ms = – ½
Q.5- Which out of NH3 and NF3 has higher dipole moment and why ? ❸
Q.6- What is meant by hybridization of atomic orbital’s ? Describe the shapes of sp, sp2, sp3 hybrid
orbital’s. ❷
Q.7- Distinguish between a sigma and a pi bond. ❸
Q.8- Electrons are emitted with zero velocity from a metal surface when it is exposed to radiation of
wavelength 6800 Å. Calculate threshold frequency (v0) and work function (W0) of the meta. ❸
Q.9- (a) What is the Hund rule ? ❷
(b) Write the electronic configurations of Cr and Cu ? ❷
Q.10- If the velocity of the electron in Bohr’s orbit is 2.19x106 m s–1, calculate the de Broglie wavelength
associated with it. ❸
Chemistry By Rajnish Goswami Sir 9828411199
Objective Type Questions
Q.11 The energy of electron in first Bohr’s orbit of H-atom is –13.6 eV. What will be its potential energy in n = 4th
orbit - ❶
(A) – 13.6 eV (B) –3.4 eV (C) –0.85 eV (D) –1.70 eV
Q.12 The correct expression derived for the energy of an electron in the nth energy level is for H-atom- ❶
2 2 me4 2 2 me4
(A) En = (B) En = –
n 2h 2 nh 2
2 2 me2 2 2 me4
(C) En = – (D) En= –
n 2h 2 n 2h 2
Q.13 The velocity of an electron in the third orbit of hydrogen atom - ❶
(A) 7.28 x107 cm sec–1 (B) 7.08 x 107 cm sec–1
(C) 7.38 x 107cm sec–1 (D) 7.48 x107cm sec–1
Q.14 The maximum number of electrons in a principal shell is - ❶
(A) 2n (B) 2n2 (C) 2 (D) 2 n
Q.15 Which of the following statements concerning the four quantum numbers is false - ❶
(A) n gives idea of the size of an orbital
(B) gives the shape of an orbital
(C) m gives the energy of the electron in the orbital
(D) s gives the direction of spin of the electron in an orbital
Q.16 The shape of the orbital is given by - ❶
(A) Spin quantum number (B) Magnetic quantum number
(C) Azimuthal quantum number (D) Principal quantum number
Q.17 The set of quantum numbers not applicable for an electron in an atom is – ❶
(A) n = 1, = 1, m = 1, s = + 1/2 (B) n = 1, = 0, m = 0, s = + 1/2
(C) n = 1, = 0, m = 0, s = – 1/2 (D) n = 2, = 0, m = 0, s = + 1/2
Q.18 Which of the following set of elements obeyes Newland’s octave rule - ❶
(A) Na, K, Rb (B) F, Cl, Br (C) Be, Mg, Ca (D) B, Al, Ga
Q.19 There are 10 neutrons in the nucleus of the element zM19. It belongs to - ❶
(A) f-block (B) s-block (C) d-block (D) None of these
Q.20 The electronic configuration of an element is 1s2,2s22p6,3s23p4. The atomic number of element present just
below the above element in periodic table is - ❶
(A) 36 (B) 34 (C) 33 (D) 32
Q.21 The name ‘Rare earths’ is used for - ❶
(A) Lanthanides only (B) Actinides only
(C) Both lanthanides and actinides (D) Alakaline earth metals
Q.22 Arrange in the increasing order of atomic radii of the following elements O, C, F, Cl, Br - ❶
(A) F < O < C < Cl < Br (B) F < C < O < Cl < Br
(C) F < Cl < Br < O < C (D) C < O < F < Cl < Br
Chemistry By Rajnish Goswami Sir 9828411199
Q.23 Which group of atoms have nearly same atomic radius - ❶
(A) Na, K, Rb, Cs (B) Li, Be, B, C (C) Fe, Co, Ni (D) F, Cl, Br, I
Q.24 The maximum tendency to form unipositive ion is for the elment with the electronic configuration- ❶
(A) 1s2, 2s2, 2p6, 3s2 (B) 1s2, 2s22p6, 3s23p1
(C) 1s2, 2s22p6, 3s23p2 (D) 1s2, 2s22p6, 3s23p3
Q.25 Ionic compounds in general possess both: ❶
(A) High melting points and non-directional bonds
(B) High melting points and low boiling points
(C) Directional bonds and low boiling points
(D) High solubilities in polar and non-polar solvents
Q.26 Correct order of covalent character of alkaline earth metal chloride in: ❶
(A) BeCl2 < MgCl2 < CaCl2 < SrCl2 (B) BeCl2 < CaCl2 < SrCl2 < MgCl2
(C) BeCl2 > MgCl2 > CaCl2 > SrCl2 (D) SrCl2 > BeCl2 > CaCl2 > MgCl2
Q.27 A covalent bond is possible between: ❶
(A) Similar atoms (B) Dissimilar atoms
(C) Similar and dissimilar atoms (D) Similar molecules
Q.28 The correct statement for the reaction ❶
NH3 + H+ NH4+
(A) Hybridisation state is changed (B) Bond angle increases
(C) NH3 act as a Lewis acid (D) Regular geometry is changed
Q.29 The hydrogen bond is strongest in: ❶
(A) O – H - - - S (B) S – H - - - O
(C) F – H - - - F (D) O – H - - - O
Q.30 The strength of bonds by 2s – 2s, 2p – 2p and 2p – 2s overlapping has the order: ❶
(A) s – s > p – p > s – p (B) s – s > s – p > p – p
(C) p – p > s – p > s – s (D) p – p > s – s > s – p
Chemistry By Rajnish Goswami Sir 9828411199
