Covalent bonding electronegativity Fajan's rule and dipole moment - Question Bank

1. Which of the following compounds has the highest dipole moment?
A) CH3Cl
B) CH2Cl2
C) CHCl3
D) CCl4
2. The most electronegative element in the second period is:
A) Lithium
B) Carbon
C) Nitrogen
D) Fluorine
3. Fajan's rules are based on the concept of:
A) Electron repulsion theory
B) Polarization of the anion by the cation
C) Metallic bonding
D) Quantum mechanical tunneling
4. Which of the following is NOT a consequence of dipole moment?
A) Intermolecular forces
B) Solubility in polar solvents
C) Boiling point elevation
D) Molecular shape determination
5. The dipole moment of CO is approximately 0.12 D, while that of NO is approximately 0.16 D. This difference is primarily due to:
A) The difference in bond length
B) The difference in electronegativity between C and O versus N and O
C) The molecular geometry
D) The number of lone pairs
6. Fajan's rule implies that the bond between a large cation and a large anion is more likely to be:
A) Ionic
B) Covalent
C) Metallic
D) Hydrogen bonded
7. In the series H2O, H2S, H2Se, H2Te, the dipole moment decreases in the order:
A) H2O > H2S > H2Se > H2Te
B) H2Te > H2Se > H2S > H2O
C) H2O > H2Se > H2S > H2Te
D) H2S > H2O > H2Se > H2Te
8. Which of the following elements has the lowest electronegativity?
A) Sodium
B) Potassium
C) Lithium
D) Cesium
9. The percentage ionic character of a bond can be estimated from the ratio of its observed dipole moment to the theoretical dipole moment of:
A) A pure covalent bond
B) A bond with 100% ionic character
C) A bond with 50% ionic character
D) A coordinate covalent bond
10. Which of the following factors does NOT influence the dipole moment of a molecule?
A) Electronegativity difference between atoms
B) Molecular geometry
C) Presence of lone pairs on the central atom
D) Bond length only
11. According to Fajan's rules, a cation with a d10 electron configuration will have:
A) Low polarizing power
B) High polarizing power
C) No polarizing power
D) Ionic character
12. The electronegativity of Carbon is approximately 2.55. The bond between Carbon and Hydrogen (electronegativity 2.20) is:
A) Ionic
B) Highly polar covalent
C) Slightly polar covalent
D) Non-polar covalent
13. A zero dipole moment indicates that a molecule is:
A) Always ionic
B) Always non-polar
C) Always polar
D) Can be polar or non-polar depending on bond polarity
14. Fajan's rule states that the polarization of an anion increases with:
A) Increasing size of the anion and increasing charge on the cation
B) Decreasing size of the anion and decreasing charge on the cation
C) Increasing size of the cation and decreasing charge on the anion
D) Decreasing size of the cation and increasing charge on the anion
15. Which of the following has the highest covalent character?
A) NaF
B) NaCl
C) NaBr
D) NaI
16. The dipole moment of NH3 is greater than that of NF3, even though Fluorine is more electronegative than Hydrogen. This is because:
A) The bond dipoles in NH3 align with the lone pair dipole, while in NF3 they oppose it.
B) The bond dipoles in NF3 align with the lone pair dipole, while in NH3 they oppose it.
C) NH3 is linear and NF3 is trigonal planar.
D) Nitrogen is more electronegative than Fluorine.
17. In which of the following compounds does the cation have the highest polarizing power?
A) NaCl
B) MgCl2
C) AlCl3
D) SiCl4
18. What is the typical electronegativity of Oxygen on the Pauling scale?
A) 2.5
B) 3.0
C) 3.5
D) 4.0
19. Which of the following is the most polar molecule?
A) CO
B) N2
C) O2
D) Cl2
20. Fajan's rules primarily apply to ionic compounds to predict the extent of:
A) Ionic character
B) Metallic character
C) Covalent character
D) Hydrogen bonding
21. The electronegativity difference between two atoms A and B is 1.7. The bond between A and B is considered:
A) Pure covalent
B) Polar covalent
C) Ionic
D) Coordinate covalent
22. Which molecule has polar bonds but a zero dipole moment?
A) SO2
B) NF3
C) CCl4
D) HCN
23. According to Fajan's rules, increased covalent character in an ionic compound is favored by:
A) A large cation and a small anion
B) A small cation and a large anion
C) A large cation and a large anion
D) A small cation and a small anion
24. The 'dipole moment' is a vector quantity. Its direction is from:
A) Positive pole to negative pole
B) Negative pole to positive pole
C) Atom with higher electronegativity to lower electronegativity
D) Atom with lower electronegativity to higher electronegativity
25. Which of the following pairs has the most polar covalent bond?
A) H-Cl
B) H-Br
C) H-I
D) H-F
26. Electronegativity is a measure of the ability of an atom to:
A) Donate electrons
B) Attract electrons in a covalent bond
C) Accept electrons to form an anion
D) Share electrons equally
27. Fajan's rules state that a smaller cation with a higher positive charge will:
A) Have less polarizing power
B) Induce more polarization in the anion
C) Form a more ionic bond
D) Have a larger ionic radius
28. Which of the following is the correct trend for dipole moment in the given hydrides?
A) CH4 > SiH4 > GeH4
B) NH3 > PH3 > AsH3
C) H2O > H2S > H2Se
D) HCl > HBr > HI
29. A molecule with polar bonds can be nonpolar if:
A) It has a linear shape
B) It has a symmetrical shape and the bond dipoles cancel out
C) It has a high molecular weight
D) It contains only single bonds
30. Consider the series LiCl, NaCl, KCl, CsCl. The covalent character increases in the order:
A) LiCl < NaCl < KCl < CsCl
B) CsCl < KCl < NaCl < LiCl
C) NaCl < KCl < LiCl < CsCl
D) KCl < NaCl < CsCl < LiCl
31. Which element has an electronegativity value of approximately 4.0 on the Pauling scale?
A) Chlorine
B) Bromine
C) Iodine
D) Fluorine
32. The sum of dipole moments of individual polar bonds in a molecule gives the:
A) Average bond polarity
B) Net dipole moment of the molecule
C) Bond order
D) Dipole moment of the strongest bond
33. Which of the following is NOT a factor influencing electronegativity according to Fajan's rules?
A) Charge on the cation
B) Size of the cation
C) Size of the anion
D) Number of valence electrons
34. The dipole moment of HCl is 1.03 D. If the bond length is 1.27 Å, what is the percentage of ionic character in HCl?
A) 5%
B) 17%
C) 35%
D) 70%
35. Fajan's rules suggest that covalent character is enhanced when the cation has:
A) A stable noble gas configuration
B) A high number of d-electrons
C) A large ionic radius
D) A high charge density
36. Which bond has the most polar character?
A) C-H
B) N-H
C) O-H
D) F-H
37. In the molecule BF3, the B-F bonds are polar, but the molecule itself is nonpolar. This is due to:
A) The presence of lone pairs on Boron
B) The symmetrical trigonal planar geometry
C) The low electronegativity of Boron
D) The high electronegativity of Fluorine
38. Which of the following statements about electronegativity is FALSE?
A) It generally increases across a period.
B) It generally decreases down a group.
C) Fluorine is the most electronegative element.
D) Noble gases have high electronegativity values.
39. The unit of dipole moment is typically expressed in:
A) Volt
B) Ampere
C) Debye
D) Ohm
40. Which of the following molecules is polar?
A) CH4
B) CO2
C) H2O
D) N2
41. According to Fajan's rules, what characteristic of an anion favors greater covalent character?
A) Small size and high charge
B) Large size and low charge
C) Small size and low charge
D) Large size and high charge
42. What is the correct order of increasing electronegativity?
A) O < N < C < H
B) H < C < N < O
C) C < H < N < O
D) H < N < C < O
43. A bond formed between two atoms with a large difference in electronegativity is likely to be:
A) Pure covalent
B) Non-polar covalent
C) Ionic
D) Metallic
44. Which of the following compounds exhibits the highest ionic character?
A) NaCl
B) KCl
C) CsCl
D) LiCl
45. The dipole moment of a molecule is a measure of its:
A) Bond strength
B) Ionic character
C) Polarity
D) Molecular weight
46. Which factor increases the polarity of a covalent bond?
A) Equal electronegativity of bonded atoms
B) Large difference in electronegativity between bonded atoms
C) Non-polar molecular geometry
D) Presence of lone pairs only
47. Fajan's rules primarily explain the degree of covalent character in which type of bond?
A) Metallic bond
B) Ionic bond
C) Covalent bond
D) Hydrogen bond
48. Which molecule has a net dipole moment of zero due to its symmetrical structure?
A) Water (H2O)
B) Ammonia (NH3)
C) Carbon Dioxide (CO2)
D) Hydrogen Chloride (HCl)
49. What is the approximate electronegativity value of Hydrogen on the Pauling scale?
A) 1.2
B) 2.1
C) 3.0
D) 4.0
50. According to Fajan's rules, what characteristic of a cation favors greater covalent character in an ionic bond?
A) Large size and low charge
B) Small size and high charge
C) Large size and high charge
D) Small size and low charge