F-Block Elements MCQs [Chemistry]

1. The lanthanides contraction is responsible for the fact that

(A) Zr and Y have about the same radius

(B) Zr and Hf have about the same radius

(C) Zr and Zn have the same oxidation state

(D) Zr and Nb have similar oxidation states

2. How many elements are members of lanthanides?

(A) 12

(B) 15

(C) 14

(D) 13

3. Which of the mentioned are important minerals of lanthanides?

(A) All A, B, and C

(B) Euxenite

(C) Monazite

(D) Xenotime

4. What is the % of Ce-earths in Monazite?

(A) 30-40%

(B) 50-60%

(C) 40-50%

(D) 50-70%

5. Which of the mentioned statements is not true with regard to misch metals use?

(A) These are used to produce bullets shell

(B) These are used to produce lighter flints

(C) These are used in petroleum cracking

(D) The traces of Cs and Na are present in misch metals

6. Which of the mentioned classical methods is used to separate lanthanides?

(A) Fractional thermal decomposition

(B) Fractional precipitation

(C) Fractional crystallization

(D) All A, B, and C

7. Which of the mentioned modern methods is used to separate lanthanides?

(A) TLC

(B) Complex formation

(C) Ion-exchange

(D) All A, B, and C

8. Which are the elements in which the additional electron enters (n-2) f orbital?

(A) s block elements

(B) p block elements

(C) f-block elements

(D) d-block elements

9. What is the another name for 4f block elements?

(A) Rare-earths

(B) Lanthanones

(C) All A, B, and C

(D) Lanthanides

10. The +2 and +4 oxidation states is shown by which lanthanides?

(A) Ce

(B) Sm

(C) Er

(D) Lu

11. The lanthanide contraction is due to decrease in

(A) Electron affinity

(B) Metallic character

(C) Ionic size

(D) Electronegativity

12. Which of the mentioned is not member of lanthanides?

(A) Gd

(B) Sm

(C) Ca

(D) Lu

13. Which of the following are the elements in which the extra electron enters 5f-orbitals of the (n-2)th main shell?

(A) Actinones

(B) Actinides

(C) 5f-block elements

(D) All A, B, and C

14. Which of the mentioned does not belong to actinides?

(A) Bk

(B) Th

(C) Es

(D) Am

15. Which of the mentioned organic solvents is commonly used for separation of actinides?

(A) All A, B, and C

(B) Hexone

(C) TBP

(D) Diethyl ether

16. Which of the mentioned elements shows maximum variable oxidation states among the actinides?

(A) All A, B, and C

(B) Am

(C) Np

(D) Pu

17. Which of the mentioned elements shows +2 oxidation states among the actinides?

(A) Th

(B) U

(C) Am

(D) Ac

18. Which of the mentioned elements shows only +4 oxidation state among the actinides?

(A) Ac

(B) Th

(C) U

(D) Am

19. What is the % of Ye-earths in Xenotime?

(A) 50-60%

(B) 54-65%

(C) 40-50%

(D) 30-40%

20. What is the location of significant deposits of lanthanides?

(A) South Africa

(B) All A, B, and C

(C) USA

(D) Brazil

21. Which of the mentioned is not a member of lanthanides?

(A) La

(B) Sm

(C) Nd

(D) Ba

22. Which of the mentioned elements shows only +3 oxidation state among the actinides?

(A) Th

(B) U

(C) Fm

(D) U

23. Which of the mentioned elements shows color spectra among the actinides?

(A) Pu

(B) Np

(C) U

(D) All A, B, and C

24. The decrease in ionic radii of lanthanides in row is due to

(A) Different shapes of f-orbitals

(B) The attraction of ns² electrons by the nucleus

(C) Inefficient shielding of f-orbitals for the attraction of ns² electrons by the nucleus

(D) Efficient shielding of f-orbitals for the attraction of ns² electrons by the nucleus

25. Which of the mentioned hydroxides is more basic?

(A) Lu(OH)₃

(B) La(OH)₃

(C) Er(OH)₃

(D) Sm(OH)₃

26. Which of the mentioned elements shows maximum number of different oxidation states in its compounds?

(A) Am

(B) La

(C) Eu

(D) Gd

27. Which of the mentioned statements is false?

(A) In lanthanide the ionic radius of Ln³⁺ ion decreases

(B) La(OH)₃ is less basic than Lu(OH)₃

(C) La is an element of transition series

(D) Zr and Hf have about the same radius due to lanthanide contraction

28. An alloy of cerium and iron is known as _________.

(A) Auer metal

(B) Metal

(C) Brass

(D) Zircona

29. Which of the mentioned statements is not true with regard to actinides?

(A) Actinides are heavy metals

(B) They are radioactive and toxic to humans

(C) Their nuclear stability decreases with increasing atomic number

(D) Ac usually shows oxidation state of 5+

30. Which of the mentioned minerals is not a member of cerium group of minerals?

(A) Monazite

(B) Cerite

(C) Euxenite

(D) Bastaesite

31. Which of the mentioned minerals is not belonging to carbonate group?

(A) Parasite

(B) Ancylite

(C) Bastaesite

(D) Euxenite

32. Which of the mentioned minerals is not belonging to phosphate group?

(A) Bastaesite

(B) Britholite

(C) Monazite

(D) Xenotime

33. Which of the mentioned statements is not true with regard to lanthanides?

(A) Lanthanides are very reactive metals

(B) The coordination number of lanthanides is small

(C) Most of the compounds of lanthanides are paramagnetic

(D) Lanthanides are very strong reducing agents

34. Which of the mentioned members of lanthanides has larger ionic radius?

(A) Er³⁺

(B) Ce³⁺

(C) Sm³⁺

(D) Eu³⁺

35. The color of lanthanides is due to

(A) f-f transitions

(B) s-p transitions

(C) d-d transitions

(D) d-f transitions

36. The alloys of lanthanides are known as

(A) Coinage metals

(B) Precious metals

(C) Misch metals

(D) None of A, B, and C

37. Which of the mentioned minerals is not a member of yttrium group of minerals?

(A) Monazite

(B) Euxenite

(C) Gadolinite

(D) Xenotime

38. Which of the mentioned statements is not true with regard to lanthanides?

(A) The hardness of metals decreases with an increase in atomic number

(B) Basicity of lanthanide decreases with increase in atomic number

(C) Most of the trivalent ions are colored

(D) Lanthanides are silvery white soft metals

39. Which of the following are the alloys of lanthanides with other metals?

(A) Brass

(B) Bronze

(C) Misch metals

(D) Steel

40. A typical misch metal consists of

(A) Lanthanide metal – 80% and iron – 20%

(B) Lanthanide metal – 85% and iron – 15%

(C) Lanthanide metal – 50% and iron – 50%

(D) Lanthanide metal ~95% and iron – 5%

41. The lanthanides are used in

(A) Abrasives

(B) Nuclear industry

(C) Paints

(D) All A, B, and C

42. The common oxidation state of lanthanides is

(A) +1

(B) +3

(C) +2

(D) +5