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 Multiple Choice QuestionsMultiple Choice Questions

251.

Chemical bond implies

  • attraction and repulsion

  • attraetion and repulsion balanced at a particular distance

  • attraction

  • repulsion


252.

The percentage s-character of the hybrid orbitals in methane, ethene and ethyne are respectively

  • 25, 33, 50

  • 25, 50, 75

  • 50, 75, 100

  • 10, 20, 40


253.

Which of the following represents the Lewis structure of N2 molecule?


254.

For a stable molecule, the value of bond order must be

  • there is no relationship between stability and bond order

  • zero

  • positive

  • negative


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255.

Which of the following has the highest bond order?

  • N2

  • O2

  • He2

  • H2


A.

N2

Molecular orbital configuration ofN2 = 14e-= σ1s2, σ*1s2, σ2s2, σ*2s2,σ2px2, π2py2, π2pz2Bond order =Nb- Na2= 10-42=3similarly for O2 molecule, bond order = 2For He2 molecule, bond order = 0For H2 molecule bond oeder = 1So, N2 has highest bond order.


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256.

During the formation of a chemical bond

  • electron-electron repulsion becomes more than the nucleus-electron attraction.

  • energy of the system does not change.

  • energy increases

  • energy decreases


257.

Which of the following is diamagnetic?

  • H2+

  • O2

  • Li2

  • He2+


258.

In acetylene molecule, between the carbon atoms there are

  • three pi bonds

  • one sigma and two pi bonds

  • two sigma and one pi bonds

  • three sigma bonds


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259.

The number of nodal planes present in σ* antibonding orbitals is

  • 1

  • 2

  • 0

  • 3


260.

The overlapping of orbitals in benzene is of the type

  • sp-sp

  • p-p

  • sp2-sp2

  • sp3-sp3


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