F-Block Elements MCQ Assignment 5 - ChemContent

Vijay Ishwar
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14 F-Block Elements MCQ Questions are given on this page. These questions have been asked in previous year exams of CSIR NET, GATE, TIFR, BARC etc. Test your knowledge by trying these simple MCQs and match your answers with the answer key provided at the bottom of the page. 

Also note, you can attempt this assignment as a quiz where you can mark options, calculate your score and see which questions you attempted were correct and which were not. For doing so, go to Quiz link. To download the assignment in PDF format, click PDF.

Good Luck! 😊😉

Quiz        PDF

Q1 Coordination number and geometry of [Ce(NO3)6]2- is

         (a) 6, octahedral

         (b) 12, octahedral

         (c) 8, dodecahedral

         (d) 12, icosahedral

Q2 The tri-positive lanthanides ion which does not show sharp peak in its' adsorption spectrum?

         (a) Ce3+

         (b) Pr3+

         (c) Gd3+

         (d) Pm3+

Q3 Ce3+ is colorless whereas Ce4+ is colored because

(a) In Ce3+ there is f-f transition in UV region and in Ce4+ there is f-f transition in visible region.

(b) In Ce3+ there is f-d transition in UV region and in Ce4+ there is f-f transition in visible region.

(c)  In Ce3+ there is f-d transition in UV region and in Ce4+ there is charge transfer in visible region.

(d) Ce3+ there is f-f transition in UV region and in Ce4+ there is charge transfer in visible region.

Q4 The element for which there is no good agreement between experiment and calculated value of magnetic moment is:

         (a) Eu3+

         (b) Nd3+

         (c) Ho3+

         (d) Pr3+

Q5 The size of Mo/W pair is almost similar because of

         (a) Orbital contribution

         (b) Lanthanide contraction

         (c) Spin-orbit coupling

         (d) Both belong to the same period

Q6 The enrichment of uranium is carried out in form of

         (a) UO23+

         (b) UO22+

         (c) UF6

         (d) U[(acac)3]3+

Q7 The valance shell electronic configuration of neutral 64Gd is:

         (a) 4f7 5d1 6s2

         (b) 4f7 5d2 6s1

         (c) 4f8 5d0 6s2

         (d) 4f6 5d2 6s2

Q8 Which of the following pair of 4f elements can exhibit +4 oxidation state?

         (a) La and Lu

         (b) Ce and Pr

         (c) Eu and Yb

         (d) Sm and Tm

Q9 Ligand field stabilization energies are smaller for lanthanides compared to transition metals in the same oxidation states because

         (a) size of lanthanide ion is larger.

         (b) f orbital interacts less efficiently with ligands.

         (c) size of lanthanide ion is smaller.

         (d) lanthanide favour oxygen ligands.

Q10 The experimentally observed magnetic moment values, which match well with spin-only values for the pair of aqueous ions is

[GATE 2019]

(Atomic numbers: Cr=24, Co=27, Gd=64, Tb=65, Dy=66 and Lu=71)

         (a) Cr(III) and Gd(III)

         (b) Co(II) and Gd(III)

         (c) Cr(III) and Dy(III)

         (d) Lu(III) and Tb(III)

Q11 The experimental magnetic moment (3.4 BM) of a hydrated salt of Eu3+ at 27º C is significantly different from the calculated value.
The difference is due to

[GATE 2020]

(a) population of electrons at higher J levels

(b) strong ligand field splitting of f-orbitals

(c) strong spin-orbit coupling

(d) pairing of electrons in f-orbitals

Q12 Pair of lanthanide ions which show significant deviation between the experimental and calculated magnetic moments, considering contribution from the ground state only, is
(Given that ueff = g[J(J+1)]1/2)

[NET Dec 2019]

         (a) Gd3+ and Lu3+

         (b) Sm3+ and Tb3+

         (c) Eu3+ and Tb3+

         (d) Sm3+ and Eu3+

Q13 Consider the following statements for Eu3+

[NET Dec 2018]

(A) The positions of sharp band in UV-vis spectra of it's complexes depend heavily on the ligand environment.

(B) Its' ground state term symbol is 7F0

(C) The observed magnetic moment is due to populated higher J level

(D) At 2K its' magnetic moment approaches to zero

The correct set of statements is

         (a) A, Cand D

         (b) B, C and D

         (c) A, B and D

         (d) A, B and C

Q14 The coordination number of Gd in GdCl3.6H2O is

[NET June 2019]

(a) 3

(b) 6

(c) 8

(d) 9

Ans Key

1.d  2.a  3.c  4.a  5.b  6.c  7.a  8.b  9.b  10.a  11.a   12.d  13.b  14.c

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