Which one of the followmg has no unpaired electrons? from Chemis

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 Multiple Choice QuestionsMultiple Choice Questions

461.

The set of quantum numbers for the outermost electron for copper in its ground state is

  • 4, 1, 1 +1/2

  • 3, 2, 2, +1/2

  • 4, 0, 0, +1/2

  • 4, 2, 2, +1/2


462.

Which one of the following sets of quantum numbers represents the highest energy level in an atom?

  • n = 4, l = 0, m = 0, s = +12

  • n = 3, l = 1, m = 1, s = +12

  • n = 3, l = 2, m = -2, s = +12

  • n = 3, l = 0, m = 0, s = +12


463.

If the energies of the two photons in the ratio of 3 : 2, their wavelength will be in the ratio of

  • 2 : 3

  • 9 : 4

  • 3 : 2

  • 1 : 2


464.

The spin only magnetic moment of Fe2+ ion (in BM) is approximately

  • 4

  • 7

  • 5

  • 6


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465.

In an alkaline medium, glycine predominantly exists as/ in a/ an

  • cation

  • anion

  • Zwitter ion

  • covalent form


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466.

Which one of the followmg has no unpaired electrons?

  • O2-

  • O2+

  • O22-

  • O2


C.

O22-

(i) In O2- total number of electrons = 16 + 1 = 17

 Orbital arrangement

= KK', σ2s2, σ*2s2, σ2pz2, π2px2 = π2py2, π*2px2 = π*2py1

(ii) In O2+, total number of electrons = 16 - 1 = 15

 Orbital arrangement 

= KK', σ2s2, σ*2s2, σ2pz2, π2px2  π2py2, π*2px1

(iii) In O22-, total number of electrons = 16 + 2 = 18

 Orbital arrangement

= KK', σ2s2, σ*2s2, σ2pz2, π2px2  π2py2, π*2px2  π*2py2

(iv) In O2, total number of electrons = 16

 Orbital arrangement 

= KK', σ2s2, σ*2s2, σ2pz2, π2px2  π2py2, π*2px1  π*2py1

Hence, only O22- has no unpaired electrons.


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467.

The "spin only'' magnetic moment of Ni2+ in aqueous solution would be [At. no. of Ni = 28]

  • 15 BM

  • 2 BM

  • 8 BM

  • 6 BM


468.

The correct set of four quantum numbers for the outermost electron of sodium (Z = 11) is

  • 3, 1, 1, 12

  • 3, 2, 1, 12

  • 3, 0, 0, 12

  • 3, 1, 0, 12


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469.

The statement that is not correct is

  • Angular quantum number signifies the shape of the orbital

  • Energies of stationary states in hydrogen like atoms is inversely proportional to the square of the principal quantum number

  • Total number of nodes for 3s-orbital is three

  • The radius of the first orbit of He is half that of the first orbit of hydrogen atom


470.

The two electrons have the following set of quantum numbers, P =3,2, -2 +1/2, Q =3,0,0 + 1/2. Which of the following statement is true?

  • P and Q have same energy

  • P has greater energy than Q

  • P has lesser energy than Q

  • P and Q represent same electron


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