D and F Block Elements MCQ: Class 12 students preparing for the CBSE Board Exams next year should start practicing important questions now to avoid last-minute stress. Early preparation helps you manage your studies better and identify weak areas, giving you ample time to revise and improve. This approach will boost your confidence and enhance your exam performance.
This article provides a collection of crucial MCQs for CBSE Class 12 Chemistry Chapter – The d and f Block Elements. The questions and answers are curated by subject matter experts and cover all key concepts from the chapter, aligned with the revised CBSE Syllabus for Class 12 Chemistry. These questions are valuable resources for board exam preparation. You can access all the MCQs for CBSE Class 12 Chemistry Chapter 4 – The d and f Block Elements here and download them using the link at the end of this article.
The elements in groups 3–12 are known as d-block elements, where d-orbitals are gradually filled as periods increase. The f-block elements, separated at the bottom of the periodic table, have 4 and 5 f orbitals that are gradually filled.
Also Read Class 12 Other Chapters MCQs:
- Coordinate Compounds MCQs
- Nernst Equation MCQ
- Chemistry in Everyday Life MCQs
- Chemical Kinematics MCQs
- Amines MCQs
Class 12 D and F Block Elements Chemistry MCQ
Ques 1. What is the oxidation number of gold?
a) +1
b) 0
c) -1
d) All of these
Answer: a
Ques 2. Which metal has the lowest melting point?
a) Cs
b) Na
c) Hg
d) Sn
Answer: c
Ques 3. Which group of elements do transition elements belong to?
a) p-block
b) s-block
c) d-block
d) f-block
Answer: c
Ques 4. The total number of unpaired electrons in Mn³⁺, Cr³⁺, and V³⁺ gaseous species is, and the most stable species is
a) 4, 3, and 2; V³⁺
b) 3, 3, and 2; Cr³⁺
c) 4, 3, and 2; Cr³⁺
d) 3, 3, and 3; Mn³⁺
Answer: c
Also Check: The d and f Block Elements Class 12 Notes Chemistry Chapter 8
Ques 5. In alkaline solution, MnO₄⁻ changes to
a) MnO₄²⁻
b) MnO₂
c) Mn₂O₃
d) MnO
Answer: b
Ques 6. Which of the following pairs of ions has the same electronic configuration?
a) Cu²⁺, Cr²⁺
b) Fe³⁺, Mn²⁺
c) Co³⁺, Ni³⁺
d) Sc³⁺, Cr³⁺
Answer: b
Ques 7. The electrical configuration of the alkaline earth element is
a) ns²
b) ns¹
c) np⁶
d) ns⁰
Answer: a
Ques 8. As an electroplated protective covering, what metal is used?
a) Plutonium
b) Chromium
c) Nickel
d) Iron
Answer: b
Ques 9. __________ possesses the properties of both alkali metals and halogens.
a) Helium
b) Hydrogen
c) Sodium
d) Chlorine
Answer: b
Ques 10. As we proceed from left to right in groups, what happens to the non-metallic nature?
a) Remains constant
b) Decreases
c) Increases
d) Irregular
Answer: c
Ques 11. Which of the following statements concerning transuranium elements is incorrect?
a) Atomic number > 92
b) Example is Thorium
c) Decay radioactively as they are unstable
d) Elements after Uranium
Answer: b
Also Check: NCERT Solutions for Class 12 Chemistry Chapter 8 The d and f Block Elements
Ques 12. Select the appropriate statement.
a) Both actinoids and lanthanoids are less basic
b) Both actinoids and lanthanoids are electropositive
c) Both actinoids and lanthanoids do not exhibit magnetic and spectral properties
d) Both actinoids and lanthanoids do not show same oxidation of +3
Answer: b
Ques 13. What happens to the atomic size of lanthanides as the atomic number increases?
a) The radius remains unchanged
b) The radius first increases and then decreases
c) The radius increases
d) The radius decreases
Answer: d
Ques 14. Which of the following is not a lanthanide property?
a) They are soft metals with a white silvery color
b) They tarnish rapidly by air
c) The hardness of the metals increases with increase in the atomic number
d) The melting point of the metal ranges from 500-1000K
Answer: d
Ques 15. What is the lanthanide’s final element?
a) Ytterbium
b) Erbium
c) Thulium
d) Lutetium
Answer: d
Ques 16. Baeyer’s reagent is which of the following?
a) Acidified KMnO₄
b) Aqueous KMnO₄
c) Acidified K₂Cr₂O₇
d) Alkaline KMnO₄
Answer: d
Ques 17. AgCl fails to pass which of the following tests?
a) Alkaline test
b) Acidic test
c) Chromyl chloride test
d) Baeyer’s reagent test
Answer: c
Ques 18. Which of the following reasons is responsible for the formation of alloys by transition elements?
a) They have the same atomic number
b) They have the same electronic configuration
c) They have nearly the same atomic size
d) None of the above
Answer: c
Ques 19. The property which is not characteristic of transition metals is
a) Variable oxidation states
b) Tendency to form complexes
c) Formation of colored compounds
d) Natural radioactivity
Answer: d
Ques 20. The pair in which both the elements generally show only one oxidation state is
a) Sc and Zn
b) Zn and Cu
c) Cu and Ag
d) Zn and Au
Answer: a
Ques 21. Lanthanoid contraction is due to an increase in
a) Atomic number
b) Effective nuclear charge
c) Atomic radius
d) Valence electrons
Answer: b
Ques 22. Which one of the following characteristics of the transition metals is associated with higher catalytic activity?
a) High enthalpy of atomization
b) Paramagnetic behavior
c) Color of hydrate ions
d) Variable oxidation states
Answer: d
Ques 23. Zr and Hf have almost equal atomic and ionic radii because of
a) Diagonal relationship
b) Lanthanoid contraction
c) Actinoid contraction
d) Belonging to the same group
Answer: b
Ques 24. In KMnO₄, oxidation number of Mn is
a) +2
b) +4
c) +6
d) +7
Answer: d
Ques 25. Which one of the following is a diamagnetic ion?
a) Co²⁺
b) Ni²⁺
c) Cu²⁺
d) Zn²⁺
Answer: d
Also Check: Important Questions for Class 12 Chemistry Chapter 8 The d- and f-Block Elements
Ques 26. Transition elements show variable oxidation states due to the loss of electrons from which of the following orbitals?
a) ns and np
b) (n – 1) d and ns
c) (n – 1) d
d) ns
Answer: b
Ques 27. Which of the following pairs of ions have the same electronic configuration?
a) Cu²⁺, Cr²⁺
b) Fe³⁺, Mn²⁺
c) Co³⁺, Ni³⁺
d) Sc³⁺, Cr³⁺
Answer: b
Ques 28. Mohr’s salt is a
a) Normal salt
b) Acid salt
c) Basic salt
d) Double salt
Answer: d
Ques 29. Which of the following will give a pair of enantiomorphs?
a) [Cr(NH₃)₆][Co(CN)₆]
b) [Co(en)₂Cl₂]Cl
c) [Pt(NH₃)₄][PtCl₆]
d) [Co(NH₃)₄Cl₂]NO₂
Answer: b
Ques 30. Color of transition metal ions is due to absorption of the same wavelength. This results in
a) d-s transition
b) s-s transition
c) s-t transition
d) d-d transition
Answer: d
Ques 31. The melting point of copper is greater than that of zinc because
a) Copper has a bcc structure
b) Copper has a larger atomic volume
c) Copper electrons are involved in metallic bonding
d) Metallic bonding involves both the s and d electrons of copper
Answer: c
Ques 32. Which of the following does not constitute an amphoteric ion?
a) Al³⁺
b) Cr³⁺
c) Fe³⁺
d) Zn²⁺
Answer: c
Ques 33. What happens when potassium iodide reacts with an acidic potassium dichromate solution?
a) It releases iodine
b) The formation of potassium sulfate
c) The formation of chromium sulfate
d) All of the aforementioned products are created
Answer: d
Ques 34. How many moles of KMnO₄ are required to completely react with one mole of ferrous oxalate in acidic solution?
a) 3/5
b) 2/5
c) 4/5
d) 1
Answer: a
Ques 35. Acidified potassium dichromate combines with potassium iodide to form I₂. What is the chromium oxidation state in the reaction products?
a) +4
b) +6
c) +3
d) +2
Answer: c
Ques 36. In a reaction with excess KI, one mole of acidified K₂Cr₂O₇ will liberate………….. mole(s) of I₂
a) 6
b) 1
c) 7
d) 2
Answer: a
Ques 37. In the dichromate anion (Cr₂O₇²⁻)
a) All Cr – O bonds are equal
b) 6 Cr – O bonds are equal
c) Three Cr–O bonds are equivalent
d) There are no comparable bonds in Cr₂O₇²⁻
Answer: b
