MCQ(SINGLE CORRECT OPTION)

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1 MCQ(SINGLE CORRECT OTION) roblem 1: I 3 (tri-iodide ion) has (A) Linear shape (C) Trigonal planar shape (B) Angular shape (D) T-shape Central I atom in I 3 is sp 3 d hybridised. Lone pairs occupy equatorial position I I (A) I roblem 2: S O bond length in SOCl 2 (A) Equal C O bond length in COCl 2 (B) Greater than C O bond length in COCl 2 (C) Less than C O bond length in COCl 2 (D) None of the above roblem 4: N 3. It is less than C O bond length due to p d bonding (C) When N 3 is treated with Cl, state of hybridisation on central nitrogen (A) Changes from sp 3 to sp 2 (B) Remains unchanged (C) Changes from sp 3 to sp 3 d (D) Changes from sp 3 to sp On N 4 + state of hybridisation on central nitrogen atom is sp 3 as in + N roblem 4: (B) Lanthanoid ion which is most likely to be reduced by Cr(+II) is (A) Sm (B) Yu (C) Yb (D) All of the above

2 roblem 5: roblem 6: roblem 7: is roblem 8: roblem 9: All of them on being reduced will get either stable half filled orbitals or stable completely filled orbitals. (D) The correct bond order of S O bond in decreasing order is (A) OSF 2 OSCl 2 OSBr 2 (B) OSCl 2 OSBr 2 OSF 2 (C) OSF 2 OSBr 2 OSCl 2 (D) OSBr 2 OSCl 2 OSF 2 As electronegativity of halogen attached with sulphur increases, sulphur become more electron deficient and hence its tendency to get electrons from oxygen through p d bonding also increases i.e. extent of p d bonding increases and hence bond order also increases. (A) The species which does not show paramagnetism is (A) + (B) 2 (C) + (D) 2 2 has no unpaired electron (C) The shape of a molecule which has three bond pairs and one lone pairs (A) Octahedral (C) yramidal (B) Triangular planar (D) Tetrahedral i.e. N 3 has three bond pair and one lone pair. (C) Which molecule is T-shaped. (A) BeF 2 (B) BCl 3 (C) N 3 (D) ClF 3 ClF 3 has sp 3 d hybridisation with two lone pairs of electron on central Cl-atom. (D) The pair having similar geometry is (A) BF 3, N 3 (B) BF 3, AlF 3 (C) BeF 2, 2 O (D) BCl 3, Cl 3 both have sp 2 hybridisation of central atom. (B) roblem 10: ow many unpaired electrons are present in N 2 + (A) 1 (B) 2 (C) 3 (D) 4 In N 2 all electrons are paired. Thus N 2 + has one unpaired electron.

3 (A) roblem 11: roblem 12: roblem 13: Cl 5 exist, but NCl 5 does not exist because (A) Nitrogen has no vacant 2-d orbital (B) NCl 5 is unstable (C) N-atom is much smaller than (D) Nitrogen is highly inert The excitation of 2s electron is not possible (A) The following compounds have been arranged in order of their increasing thermal stabilities identify the correct order K 2 CO 3 (I) MgCO 3 (II) CaCO 3 (III) BeCO 3 (IV) (A) I II III IV (B) IV II III I (C) IV II I III (D) II IV III I The stability of carbonates increases with increasing electropositive character of metal. (B) Among the following compounds the one that is polar and has the central atoms with sp 2 hybridisation is (A) 2 CO 3 (B) SiF 4 (C) BF 3 (D) Cl Carbon in 2 CO 3 has sp 2 hybridisation and also polar. BF 3 has sp 2 hybridisation but non-polar. SiF 4 has sp 3 hybridisation. Cl has sp 3 hybridisation. (A) roblem 14: In the formation of N + 2 from N 2 the electron is removed from (A) A orbital (B) A -orbital (C) A * M orbital (D) A -M orbital See the electronic configuration of N 2 (A) roblem 15: roblem 16: C has the same geometry as (A) gcl 2 (B) N (C) C 2 2 (D) Both (A) and (C) both gcl 2 and C 2 2 are linear like C because of sp hybridisation. (D) Among the following species identify the isostructural pairs NF 3, NO 3, BF 3 3 O +, N 3 (A) [NF 3, NO 3 and [BF 3 3 O + ] (B) [NF 3, N 3 ] and [NO 3, BF 3 ] (C) [NF 3, 3 O + ] and [NO 3, BF 3 ] (D) [NF 3, 3 O + ] and [N 3, BF 3 ]

4 NF 3 and 3 O + have sp 3 hybridisation; NO 3 hybridisation (C) and BF 3 have sp 2 roblem 17: roblem 18: Among K, AlO 2, Ba and NO + 2 one unpaired electron is present in (A) O + 2 and Ba (B) K and Al (C) K only (D) Ba only K has K + structure having on unpaired electron (C) Which ion has the higher polarising power (A) Mg 2+ (B) Al 3+ (C) Ca 2+ (D) Na + small cation having higher positive charge has more polarising power (B) roblem 19 : The correct order of decreasing polarisability of ion is (A) Cl Br I F (B) F I Br Cl (C) I Br Cl F (D) F Cl Br I roblem 20: Larger the ion, more is its polarisability. (C) Amongst LiCl, RbCl, BeCl 2 and MgCl 2 the compounds with greatest and least ionic character respectively are (A) LiCl and RbCl (B) RbCl and BeCl 2 (C) RbCl and MgCl 2 (D) MgCl 2 and BeCl 2 See Fajan's rule (A) LEVEL ONE 1. Which of the following compounds is (are) non - polar (A) Cl (B) C 2 Cl 2 (C) CCl 3 (D) CCl 4 2. The types of bonds present in CuSO O are only (A) Electrovalent and covalent (B) Electrovalent and co-ordinate covalent (C) Covalent and co-ordinate covalent (D) Electrovalent 3. Donor properties of hydrides of VA group in decreasing order is (A) N 3 3 As 3 Sb 3 Bi 3 (B) Bi 3 Sb 3 As 3 3 N 3 (C) Sb 3 Bi 3 As 3 3 N 3 (D) 3 N 3 As 3 Sb 3 Bi 3

5 4. In which of the following central atom does not use sp 3 hybrid orbitals in its bonding? (A) BeF (B) (C) 3 O 3 N 2 (D) NF 3 5. XeF 2 involves hybridisation (A) sp 3 (B) sp 2 (C) sp 3 d 2 (D) None of these 6. The type of hybrid orbitals used by the chlorine atom in Cl is (A) sp 3 (B) sp 3 d (C) sp (D) None of these 7. Bond angle is minimum for (A) 2 O (C) 2 Se (B) 2 S (D) 2 Te 8. For which of the following hybridisation the bond angle is maximum (A) sp 2 (B) sp (C) sp 3 (D) dsp 2 9. The species having one unpaired electron is (A) NO (B) CO (C) CN (D) 10. Compound involving sp 3 d hybridisation is (A) BF 3 (B) F 5 (C) SF 6 (D) IF Which of the following does not have dipole moment? (A) Cl (B) C (C) N (D) S 12. The molecule that will have dipole moment (A) 2,2-Dimethyl propane (B) trans -2- butane (C) cis-3-exene (B) 2,2,3,3-Tetramethyl butane 13. Which one has minimum dipole moment (A) Butene -1 (B) Cis-2-Butene (C) trans-2-butene (D) 2-Methylpropene 14. XeF 4 has shape of (A) Trigonal bipyramidal (C) Tetrahedral (B) square planar (D) none of these 15. Which of the following has minimum bond length (A) (B) O (C) 16. Which of the following is diamagnetic (D) 2 2

6 (A) (C) (B) (D) Which of the following species is paramagnetic (A) (B) CN (C) CO (D) NO Dipole moment is shown by (A) 1,4-Dichlorobenzene (C) trans -1,2-Dichloroethene (B) Cis-1,2,Dichloroethene (D) 1,4-dimethyl benzene 19. Which of the following has highest bond order (A) (B) O (C) (D) 20. Which of the following has lowest bond order? (A) (B) O (C) (D) LEVEL TWO 1. The ion which is isoelectronic with CO is (A) CN (B) (C) (D) O 2 N 2 2. Which of the following structures are isoelectronc (I) C 3 (II) 3 O + (III) N 3 (IV) C 3 (A) I and II (B) III and IV (C) I and III (D) II,III and IV 3. C is isostructural with + (A) N (B) SnCl 2 (C) C 2 4 (D) N 4. Which of the following has tetrahedral disposition? (A) S (B) S (C) SO (D) SO Which is incorrect statement? (A) C is a monomer while Si is a three dimensional giant molecule. (B) Graphite is anisotropic with respect to electricity 2 3

7 (C) (C 3 ) 3 N has C N C bond angle of whereas in (Si 3 ) 3 N has Si N Si a bond angle of 120. (D) Bond lengths of four apical O bonds are greater than calculated. 6. Which of the following cannot exist on the basis of MO theory (A) 2 (B) e 2 (C) e 2 (D) 7. Which of the following has a bond order of 2.5? (A) CO (B) NO (C) e 2+ (D) 8. Which of the following have identical bond order (I) CN (II) (III) NO + (IV) CN + (A) I & II (B) I & III (C) II & III (D) III & IV 9. Which of the following species is paramagnetic (A) N 2 2 (B) (C) (D) F Which has got highest bond angle among N, NO + 2 and N (A) N + (B) N (C) N (D) All are equal 11. ighest covalent character is found in (A) CaF 2 (B) CaCl 2 (C) CaBr 2 (D) CaI (C 3 ) 3 SiO is stronger acid than (C 3 ) 3 CO because (A) Conjugate base anion in (C 3 ) 3 SiO is stabilized by Op Sid bond formation (B) Bulkiness of (C 3 ) 3 SiO anion inhibits its stabilization (C) Electronegativity of Si is greater than C (D) All of the above 13. Two elements X and Y have 2, and 7 electrons respectively in their valence shell. The expected compound formed by combination of X and Y (A) XY 2 (B) X 5 Y 2 (C) X 2 Y 5 (D) XY When N 3 is treated with Cl N bond angle (A) Increases (B) Decreases (C) Remains same (D) Depends upon temperature 15. o-nitrophenol is more volatile than p-nitro phenol because of (A) Resonance (B) resence of intermolecular hydrogen bonding in the o-isomer (C) Absence of intermolecular hydrogen bonding in the o-isomer (D) none of these 16. The correct bond order among halogens is

8 (A) F 2 Cl 2 Br 2 I 2 (B) Cl 2 F 2 Br 2 I 2 (C) Br 2 Cl 2 F 2 I 2 (D) I 2 Cl 2 Br 2 F Among the following compounds the one that is non-polar and has central atom sp 2 hybridised is (A) 2 CO 3 (B) SiF 4 (C) BF 3 (D) Cl 18. Among the following compounds which has the largest dipole moment (A) C 3 O (B) C 4 (C) CF 4 (D) C 3 F 19. Resonance is not shown by (A) C 6 6 (B) N 2 (C) CO 3 (D) Si 20. Of the following species, the one having planar structure is (A) (B) N 4 BF 4 (C) XeF 4 (D) CCl 4 ANSWER KEY LEVEL ONE 1. D 2. A 3. A 4. A 5. B 6. A 7. D 8. B 9. A 10. B 11. B 12. C 13. C 14. B 15. B 16. D 17. A 18. B 19. B 20. D

9 LEVEL TWO 1. A 2. D 3. A 4. C 5. D 6. C 7. B 8. B 9. C 10. B 11. D 12. A 13. A 14. A 15. C 16. B 17. C 18. D 19. D 20. C SUBJECTIVE roblem 1: In (C 3 ) 3 N nitrogen is sp 3 hybridized whereas in (Si 3 ) 3 N it is sp 2 hybridised why? roblem 2: In (Si 3 ) 3 N p-d bonding exists between fully filled p-orbital of nitrogen and vacant d-orbital of silicon which requires planarity in molecule that is possible only when nitrogen is sp 2 hybridised. Why does Al 2 (CO 3 ) 3 does not exist? Al +++ due to high positive charge density (small size and greater charge) polarizes CO 3 2 ion in such a way that results in formation of C and oxide of aluminium. A +++ O - C O O - roblem 3: OsO 4 exists but OsF 8 does not exist. Why? In both cases O.S. of Os in +8 but in OsO 4, Os is bonded to oxygen by 4 double bonds whereas in OsF 8, Os will have to form 8 single bonds which require much more space around central atom.

10 roblem 4: roblem 5: Why does bi 4 not exist? b(+iv) is less table than b(+ii) due to inert pair effect and therefore b(+iv) is reduced to b(+ii) by I which changes to I 2 (I is a good reducing agent) Why can gcl 2 and SnCl 2 not exist together in an aqueous solution? SnCl 2 is a reducing agent which first reduces gcl 2 to g 2 Cl 2 (white) and then to g (black) SnCl 2 + 2gCl 2 SnCl 4 + g 2 Cl 2 SnCl 2 + g 2 Cl 2 2g + SnCl 4 roblem 6: roblem 7: roblem 8: AlCl 3 is covalent but AlCl O is ionic, Why? ydration energy helps in formation of Al 3+ ion which otherwise is difficult to form. olar water molecules also stabilize Al 3+. Why Sn +2 is a reducing agent but b 2+ is not. In b inert pair effect is more pronounced than Sn and therefore stability of +II O.S. is higher than that in Sn. White phosphorus is more reactive than red phosphorus. White phosphorus has following strained structure where each atom is bonded to three other phosphorus atoms by sigma bonds. In red phosphorus the molecule is somewhat relieved from this strained structure by forming a chain structure (polymer like) where one intra molecular p-p bond is replaced by two intermolecular p-p bonds roblem 9: Though Cs is most electropositive element in periodic table Li has highest oxidation potential why?

11 roblem 10: A metal ionizes in following way in gaseous state M M + (g) + 1e = I.E. (1) But in water cation undergoes hydration M + (g) + n 2 O [M( 2 O) n ] + = hydration energy (2) I.E. has positive value but hydration energy has ve value. For Cs I.E. is less than Li but for Li hydration energy is more than Cs as Li + has higher charge density. The resultant of these two values is more ve for Li rather than Cs. Therefore in aqueous solution Li ionizes more than Cs. Though Li + ion is smaller than Cs + ion its mobility in aqueous solution is more than Cs + ion. Due to higher +ve charge density on Li + (smaller size) hydration of Li + takes place to a greater extent than Cs + ion. As Li + gets attached to greater number of water molecules than Cs + its mobility decreases. roblem 11: BaCO 3 has got a higher decomposition temperature than MgCO 3. roblem 12: BaCO 3 has got a higher decomposition temperature the MgCO 3 which illustrates its high thermal stability. The thermal stability depends on the polarising power of the cation which in turn is inversely proportional to the radius Ba 2+ having a larger radius than Mg 2+ has got less polarising power and hence thermaly more stable. Dipole moment of BF 3 is zero. BF 3 is a planar molecule with the bond angles being 120. In each B-F bond the bond dipole is projected towards Fluorine. Now the direction of the resultant bond dipoles of these two bonds is shown in the diagram as R. If R is equal to the dipole of the 3 rd B-F bond then R and B-F dipole will neutralize each other as equal dipoles acting in opposite direction cancel each other. Now let s see the magnitude of R. As dipole moment is a vector quantity, so the resultant of two dipoles can be obtained from the law of vector addition. Suppose the bond dipole is 1. R = = a 2 b 2 2abcos F R F B 120 a & b are the individual vectors 2 1 cos120 = angle between vectors = cos120 = 2 2 F

12 = = 1 = B F R is equal in magnitude to B-F bond dipole. Similar is the case with the other two resultants. So the net dipole of BF 3 is zero. roblem 13: Compare the dipole moments of C 3 Cl, C 2 Cl 2, CCl 3, CCl 4 All the molecules have tetrahedral geometry with CCl 4 having symmetrical structure resulting in a zero dipole. C C C Cl Cl Cl Cl Cl Cl The net dipole of the molecules is the resultant of the bond dipoles. In CCl 3 due to the interaction of the non bonded electrons of chlorine the bond angle increases whereas in C 3 Cl this interaction in less and so the bond angle is less compared to CCl 3. Now the resultant dipole is dependent on cos. Now higher the value of less is cos and therefore less is the dipole moment. On that basis C 3 Cl has highest dipole and CCl 3 has lowest with CCl 4 having zero dipole. roblem 14: S is angular and C is linear why? This is because, by the method discussed above, S in S having sp 2 hybridisation with one lone pair of S occupying the sp 2 hybridised orbital gives angular shape whereas C in C is sp hybridised and is thus linear. O S O O = C = O roblem1 5: roblem 16: AlF 3 is ionic while AlCl 3 is covalent. Since F is smaller in size, its polarisability is less and therefore it is having more ionic character. Whereas Cl being large in size is having more polarisability and hence more covalent character. Ice is lighter than water. Ice is lighter then water because ice has an open cage like structure in which lesser molecules are packed per cc. Whereas in liquid water they are packed closely together. Consequently the density of water is more than ice.

13 roblem 17: roblem 8: 5 is not possible whereas F 5 is possible. Since fluorine is more electronegative it contracts the size of d-orbitals of and reduces its energy so that it can undergo hybridisation with s and p-orbitals expanding its covalency. In water the O bond angle is 105. Determine the magnitude of the charge on the oxygen atom in the water molecule. Given dipole moment of water = 1.85 D Covalent radii = ydrogen = 0.28Å Oxygen = 0.66Å O cos 52.5 = 0.94 = 0.572Å esu cm = = esu 8 d cm or 0.67 times the electronic charge. roblem1 9: What order of C bond length do you expect in C 2 6, C 2 4 and C 2 2 and why? The order of increasing C bond length is C 2 2 C 2 4 C 2 6 This is because the percentage of s-character is maximum in C 2 2 (50%) and least in C 2 6 (25%). As the % of s-character increases the bond length decreases as the extent of overlap increases. roblem 20: carbonates? Why Li 2 CO 3 decomposes on heating but not other alkali metal Since Li is very small in size, it has high polarising power which polarises CO 3 2 in C and and also due to large size difference of Li + and CO 3 2, the lattice is very much unstable and decomposes on heating.

14 LEVEL ONE 1. Why BF 3 is weaker Lewis acid than BCl 3? 2. Why [CuCl 4 ] 2 exists but [CuI 4 ] 2 does not exist? 3. SF 6 is known but SCl 6 is not known. Why? 4. Li 3 N exists but Na 3 N does not exist. Why? 5. [Al(O) 6 ] 3 exists but [B(O) 6 ] 3 does not exist. Why? 6. CCl 4 is has zero dipole moment but C 2 Cl 2 has an appreciable dipole moment. 7. CaCO 3 dissolves in Cl but not in water. 8. F from stronger -bonds than 2 O still vap of F is lower than water. 9. Valency of Fluorine is generally one whereas chlorine shows valencies of one, three, five and seven. 10. Draw the structure of the following 2 i) S 2O 3 ii) XeF 6 iii) Xe F O-nitrophenol is less soluble in water than p-nitrophenol. 12. NF 3 is pyramidal but BF 3 is planar. 13. Dipole moment of KCl is coulomb metre which indicates that it is highly polar molecule. The interatomic distance between K + and Cl is m. Calculate the dipole moment of KCl molecule if there were opposite charges of one fundamental unit located at each nucleus. Calculate the percentage ionic character of KCl. 14. bcl 4 exists but bi 4 is not possible. 15. Cl 5 exists in the solid state in the form of [Cl 4 ] + [Cl 6 ] yet it is a non conductor of electricity.

15 Level II 1. NCl 5 and BiCl 5 do not exist whereas Cl 5 exists. Why? 2. Though electronegativity difference is maximum between hydrogen and fluorine yet I is stronger acid than F. Why? 3. Why F (hydrofluoric acid) is used for etching glass? 4. F 2 bond strength is lower than Cl 2 bond strength. 5. OCl 3 molecule has the shape of an irregular tetrahedran with atom located centrally. The Cl Cl angle is found to be give a qualitative explanation for the deviation of this structure from a regular tetrahedran. 6. Li + ion has got the smallest radius among the alkali metals, yet its mobility is less than other alkali metal ions in aqueous solution. 7. Bond angle of F 2 O is 102 while that of Cl 2 O is Explain why the solubility in water of halides of Aluminium follows the order AlF 3 AlCl 3 AlBr 3 AlI 3 9. SnF 4 boils at 705C while SnCl 4 boils at Which bond is stronger F F or Cl Cl and why? 11. Formula of nitrogen is N 2 while that of phosphorus is What is the Lewis acidity order of BF 3, BCl 3, BBr 3 and BI 3 and why? 13. Why Al(O) 3 is amphoteric in nature? 14. In ICl 5, the four chlorine atoms on square planar base and the central atom I does not remain in same plane. Justify the statement. 15. o-hydroxy benzaldehyde is more soluble in water than p-hydroxy benzaldehyde.

16 LEVEL TWO 1. In (C 3 ) 3 N nitrogen is sp 3 hybridized whereas in (Si 3 ) 3 N it is sp 2 hybridised why? 2. Why 3 SiNCO is linear in vapour phase (excluding hydrogen atoms) but 3 CNCO is not linear? 3. Gold which is insoluble in all acids be is soluble in aqua-regia. Why? 4. Why SnI 4 is orange in colour? 5. Explain why C O bond length in CO is 1.128Å whereas in metal carbonyls C O bond length is 1.15Å? 6. Out of FeCl 3 and FeCl 2 which have got greater melting point and why? 7. Explain why dipole movement of p-dimethoxy benzene is non-zero? 8. Why is ortho-hydroxy benzoic acid more acidic than para-hydroxy benzoic acid? 9. C is a gas while Si in a solid. 10. The geometry of trimethyl amine and trisilyl amine is not the same. 11. Li + Li 2 O 2Na + Na 2 O Why the number of oxygen atoms combining with each metal increases. 12. AgI is least soluble of the various silver halides in water. 13. The product of hydrolysis of NCl 3 and Cl 3 are different. Why? 14. SF 6 is possible but S 6 is not possible. Why? 15. KF 2 is possible but not KCl 2. Why?

Q. No. 2 Bond formation is. Neither exothermic nor endothermic

Q. No. 2 Bond formation is. Neither exothermic nor endothermic Q. No. 1 Which combination will give the strongest ionic bond? K + and Cl - K + and O 2- Ca 2+ and Cl - Ca 2+ and O 2- In CaO, the polarizability of O 2- is very less therefore it has the maximum ionic