Periodic Table and Its Properties Exercise # 5

Exercise # 5 1. [Previous Year Questions Which one of the following ions has the highest value of ionic radius ? (1) Li+ 2. Part # I (2) B3+ (3) O2– (4) F– The formation of the oxide ion O2–(g) requires first an exothermic and then an endothermic step as shown below : O(g) + e– = O–(g) ; H° = – 142 kJmol–1 O– (g) + e– = O2– (g) ; H° = 844 kJmol–1 This is because : (1) oxygen is more electronegative. (2) oxygen has high electron affinity. (3) O– ion will tend to resist the addition of another electron. (4) O– ion has comparatively larger size than oxygen atom. 3. 4. Among Al2O3, SiO2, P2O3 and SO2 the correct order of acid strength is : (1) SO2 < P2O3 < SiO2 < Al2O3 (2) SiO2 < SO2 < Al2O3 < P2O3 (3) Al2O3 < SiO2 < SO2 < P2O3 (4) Al2O3 < SiO2 < P2O3 < SO2 Which of the following oxides is amphoteric in nature ? (1) CaO 5. (2) CO2 (3) SiO2 (4) SnO2 In which of the following arrangements the order is NOT according to the property indicated against it ? (1) Al3+ < Mg2+ < Na+ < F– – increasing ionic size (2) B < C < N < O – increasing first ionisation enthalpy (3) I < Br < F < Cl – increasing electron gain enthalpy (with negative sign) (4) Li < Na < K < Rb – increasing metallic radius 6. Which of the following factors may be regarded as the main cause of lanthanide contraction ? (1) Greater shielding of 5d electrons by 4f electrons. (2) Poorer shielding of 5d electron by 4f electrons. (3) Effective shielding of one of 4f electrons by another in the sub-shell. (4) Poor shielding of one of 4f electron by another in the sub-shell. 7. 8. The lanthanide contraction is responsible for the fact that : (1) Zr and Y have about the same radius (2) Zr and Nb have similar oxidation state (3) Zr and Hf have about the same radius (4) Zr and Zn have same oxidation state. The increasing order of the first ionization enthalpies of the elements B, P, S and F (lowest first) is : (1) F < S < P < B 9. (2) P < S < B < F (3) B < P < S < F (4) B < S < P < F Which of the following statements is true ? (1) H3PO3 is a stronger acid than H2SO3. (2) In aqueous medium, HF is a stronger acid than HCl. (3) HCIO4 is a weaker acid than HClO3. (4) HNO3 is a stronger acid than HNO2. PERIODIC TABLE AND ITS PROPERTIES 10. Lanthanoid contraction is caused due to : (1) the appreciable shielding on outer electrons by 4ƒ electrons from the nuclear charge (2) the appreciable shielding on outer electrons by 5ƒ electrons from the nuclear charge (3) the same effective nuclear charge from Ce to Lu (4) the imperfect shielding on outer electrons by 4f electrons from the nuclear charge 11. The stability of dihalides of Si, Ge, Sn and Pb increases steadily in the sequence. (1) SiX2 << GeX2 << SnX2 << PbX2 (3) GeX2 << SiX2 << SnX2 << PbX2 12. 13. (2) PbX2 << SnX2 << GeX2 << SiX2 (4) SiX2 << GeX2 << PbX2 << SnX2 The set representing the correct order of ionic radius is : (1) Na+ > Li+ > Mg2+ > Be2+ (2) Li+ > Na+ > Mg2+ > Be2+ (3) Mg2+ > Be2+ > Li+ > Na+ (4) Li+ > Be2+ > Na+ > Mg2+ In which of the following arrangements, the sequence is not strictly according to the property written against it ? (1) HF < HCl < HBr < HI : increasing acid strength (2) NH3 < PH3 < AsH3 < SbH3 : increasing basic strength (3) B < C < O < N : increasing first ionization enthalpy (4) CO2 < SiO2 < SnO2 < PbO2 : increasing oxidising power 14. The correct sequence which shows decreasing order of the ionic radii of the elements is : (1) Al3+ > Mg2+ > Na+ > F– > O2– (3) Na+ > F– > Mg2+ > O2– > Al3+ 15. The outer electron configuration of Gd (Atomic No : 64) is : (1) 4f3 5d5 6s2 16. (2) Na+ > Mg2+ > Al3+ > O2– > F– (4) O2– > F– > Na+ > Mg2+ > Al3+ (2) 4f8 5d0 6s2 (3) 4f4 5d4 6s2 (4) 4f7 5d1 6s2 Which one of the following orders presents the correct sequence of the increasing basic nature of the given oxides (1) Al2O3 < MgO < Na2O < K2O (3) Na2O < K2O < MgO < Al2O3 (2) MgO < K2O < Al2O3 < Na2O (4) K2O < Na2O < Al2O3 < MgO 17. The correct order of electron gain enthalpy with negative sign of F, Cl, Br and I, having atomic number 9, 17, 35 and 53 respectively, is: (1) F > Cl > Br > I (2) Cl > F > Br > I (3) Br > Cl > I > F (4) I > Br > Cl > F 18. The increasing order of the ionic radii of the given isoelectronic species is : (1) Cl–, Ca2+ , K+, S2– (2) S2– , Cl–, Ca2+, K+ (3) Ca2+, K+ , Cl– , S2– 19. (4) K+, S2–, Ca2+ , Cl– Which of the following represents the correct order of increasing first ionization enthalpy for Ca, Ba, S, Se and Ar ? (1) Ca < S < Ba < Se < Ar (3) Ba < Ca < Se < S < Ar (2) S < Se < Ca < Ba < Ar (4) Ca < Ba < S < Se < Ar 20. The first ionisation potential of Na is 5.1 eV. The value of electron gain enthalpy of Na+ will be : (1) –2.55 eV 21. (2) –5.1 eV 23. 24. (4) +2.55 eV The correct stastement for the molecule, CsI3 is : (1) it contains Cs3+ and I– ions. (3) it is a covalent molecule 22. (3) –10.2 eV (2) it contains Cs+, I– and lattice I2 molecule (4) it contains Cs+ and I3– ions. The ionic radii (in Å) of N3–, O2– and F– are respectively: (1) 1.71, 1.40 and 1.36 (2) 1.71, 1.36 and 1.40 (3) 1.36, 1.40 and 1.71 (4) 1.36, 1.71 and 1.40 Which of the following atoms has the highest first ionization energy? (1) Na (2) K (3) Sc (4) Rb Which of the following compounds contain (s) no covalent bond(s) ? KCl, PH3, O2, B2H6, H2SO4 (1) KCl, H2SO4 (2) KCl (3) KCl, B2H6 (4) KCl, B2H6, PH3 PERIODIC TABLE AND ITS PROPERTIES [Previous Year Questions] Part # II 1. Arrange the following oxides in the increasing order of Bronsted basicity : Hint : Consider Bronsted basicity to be simply basic strength. Cl2O7 , BaO , SO3 , CO2 , B2O3 . 2. Statement-1 : Pb4+ compounds are stronger oxidizing agents than Sn4+ compounds Statement-2 : The higher oxidation states for the group 14 elements are more stable for the heavier members of the group due to 'inert pair effect'. (A) Statement-1 is True, Statement-2 is True; Statement-2 is a correct explanation for Statement-1. (B) Statement-1 is True, Statement-2 is True; Statement-2 is NOT a correct explanation for Statement-1 (C) Statement-1 is True, Statement-2 is False (D) Statement-1 is False, Statement-2 is True 3. The increasing order of atomic radii of the following Group 13 elements is (A) Al < Ga < In < Tl (B) Ga < Al < In < Tl (C) Al < In < Ga < Tl (D) Al < Ga < Tl < In 4. The option(s) with only amphoteric oxides is(are) (A) Cr2O3, BeO, SnO, SnO2 (C) NO, B2O3, PbO, SnO2 (B) ZnO, Al2O3, PbO, PbO2 (D) Cr2O3, CrO, SnO, PbO EXERCISE - 5 : PART # I 1. 3 14. 4 2. 3 15. 4 3. 4 16. 1 4. 4 17. 2 5. 2 18. 3 6. 4 19. 3 7. 3 20. 2 8. PART # II 1. Cl2O7 < SO3 < CO2 < B2O3 < BaO 2. C 3. B 4. 4 21. 4 AB 9. 4 10. 4 11. 1 22. 1 23. 3 24. 2 12. 1 13. 2