Skip to main content
ExamCompass
Exam Compass LogoExamCompass
BlogFounderAppLogin

Exams

JEE Main & AdvancedNEET UGClass 12 BoardsClass 11 Boards

Categories

All ArticlesExam NotesRevision
Meet the FounderDownload Android & iOS AppLogin
Home/JEE MAINS/chemistry/d and f block elements
Curated PYQ Collection

Top 50 Most Repeated D AND F BLOCK ELEMENTS PYQs | JEE MAINS

A curated collection of the most important questions from D AND F BLOCK ELEMENTS, fully solved with step-by-step concepts to prepare for JEE MAINS.

Question #1

Practice Question

A.They commonly exhibit a +2 oxidation state.
B.Their 4f orbitals are progressively filled across the series.
C.They are highly electropositive and readily form +4 ions.
D.Their atomic radii increase steadily from La to Lu.

Concept Applied

Lanthanides fill the 4f subshell one electron at a time from La to Lu, leading to the lanthanide contraction. Their most stable oxidation state is +3;...

Read Full Step-by-Step Solution →

Question #2

Practice Question

A.Mn commonly exhibits oxidation states +2, +4, +7 and is paramagnetic with 5 unpaired electrons.
B.Mn shows only a single oxidation state +2 and is diamagnetic.
C.Mn exhibits oxidation states +1, +3, +5 and is ferromagnetic.
D.Mn has oxidation states +2, +3, +6 and is paramagnetic with 3 unpaired electrons.

Concept Applied

Manganese, a d‑block element, can show +2, +4 and +7 oxidation states. In the +2 state (3d⁵) all five d‑electrons are unpaired, giving a magnetic mome...

Read Full Step-by-Step Solution →

Question #3

Practice Question

Concept Applied

$ 2MnO_2 + 4KOH + O_2 \rightarrow 2K_2MnO_4 + 2H_2O $: 4 mol KOH per 2 mol $ MnO_2 $ → 2:1 ratio....

Read Full Step-by-Step Solution →

Question #4

Practice Question

A.They are chemically inert and do not conduct electricity
B.They have low melting points compared to pure metals
C.They retain metallic conductivity and are very hard
D.They are volatile and easily sublimate

Concept Applied

Interstitial compounds are formed when small atoms like H, C, or N occupy interstitial sites in transition metal lattices. These compounds retain the ...

Read Full Step-by-Step Solution →

Question #5

Practice Question

A.$\text{Fe}^{3+}$
B.$\text{Cr}^{3+}$
C.$\text{Mn}^{2+}$
D.$\text{Co}^{2+}$

Concept Applied

$\text{Mn}^{2+}$ has electronic configuration $[Ar]\,3d^5$, all 5 electrons unpaired....

Read Full Step-by-Step Solution →

Question #6

Practice Question

A.$ Fe^{3+} $
B.$ Fe $
C.$ FeO $
D.$ Fe_2O_3 $

Concept Applied

$ Cr_2O_7^{2-} $ oxidizes $ Fe^{2+} $ to $ Fe^{3+} $ in acid medium....

Read Full Step-by-Step Solution →

Question #7

Practice Question

A.Zn²⁺
B.Sc³⁺
C.Fe²⁺
D.Ti⁴⁺

Concept Applied

Fe²⁺ has unpaired electrons (paramagnetic) and exhibits +2, +3, +6 states....

Read Full Step-by-Step Solution →

Question #8

Practice Question

A.Europium
B.Gadolinium
C.Lutetium
D.Terbium

Concept Applied

Gd-157 has high neutron absorption, used in therapy and reactors....

Read Full Step-by-Step Solution →

Question #9

Practice Question

A.Variable oxidation states
B.High density
C.Low reactivity
D.Large size

Concept Applied

They provide intermediate reaction paths using variable oxidation states....

Read Full Step-by-Step Solution →

Question #10

Practice Question

A.Ethanol
B.Ethane
C.Chloroethane
D.Benzene

Concept Applied

Acidified potassium dichromate oxidizes primary alcohols to aldehydes and then carboxylic acids. Ethanol is a primary alcohol. Others are not oxidizab...

Read Full Step-by-Step Solution →

Question #11

Practice Question

A.Stainless steel
B.Brass
C.Bronze
D.Aluminium alloy

Concept Applied

In an interstitial alloy, small atoms (like carbon) occupy the interstitial spaces of a metal lattice. Stainless steel contains carbon atoms in the ir...

Read Full Step-by-Step Solution →

Question #12

Practice Question

A.Mn in KMnO₄ is +7 and Cr in K₂Cr₂O₇ is +6
B.Mn in KMnO₄ is +6 and Cr in K₂Cr₂O₇ is +6
C.Mn in KMnO₄ is +7 and Cr in K₂Cr₂O₇ is +5
D.Mn in KMnO₄ is +5 and Cr in K₂Cr₂O₇ is +6

Concept Applied

Assign oxidation numbers: In KMnO₄, K = +1, O = –2 (4 × –2 = –8). Let Mn = x. Then +1 + x – 8 = 0 ⇒ x = +7. In K₂Cr₂O₇, K = +1 (2 × +1 = +2), O = –2 (...

Read Full Step-by-Step Solution →

Question #13

Practice Question

A.They are generally soft and have low melting points because the interstitial atoms weaken metallic bonds.
B.They are generally hard and have high melting points due to small atoms occupying interstitial sites.
C.They exhibit semiconductor behavior because the interstitial atoms introduce a band gap.
D.They are always magnetic because the interstitial atoms align the d‑electron spins.

Concept Applied

In interstitial alloys, small atoms such as C or N occupy the interstitial spaces of the metal lattice, strengthening the metallic bonds. This results...

Read Full Step-by-Step Solution →

Question #14

Practice Question

A.\ce{2MnO2 + 4KOH + O2 -> 2K2MnO4 + 2H2O}
B.\ce{2K2MnO4 + Cl2 -> 2KMnO4 + 2KCl}
C.\ce{3K2MnO4 + 2H2O -> 2KMnO4 + MnO2 + 4KOH}
D.All of the above

Concept Applied

Potassium permanganate is prepared from pyrolusite (MnO₂) via a series of steps. First, MnO₂ is fused with KOH in air to form K₂MnO₄. Then, K₂MnO₄ is ...

Read Full Step-by-Step Solution →

Question #15

Practice Question

A.$\mathrm{3SO_3^{2-} + Cr_2O_7^{2-} + 8H^+ \rightarrow 3SO_4^{2-} + 2Cr^{3+} + 4H_2O}$
B.$\mathrm{3CH_3CH_2OH + 2Cr_2O_7^{2-} + 16H^+ \rightarrow 3CH_3COOH + 4Cr^{3+} + 11H_2O}$
C.$\mathrm{3H_2S + Cr_2O_7^{2-} + 8H^+ \rightarrow 3S + 2Cr^{3+} + 7H_2O}$
D.$\mathrm{5Fe^{2+} + Cr_2O_7^{2-} + 14H^+ \rightarrow 5Fe^{3+} + 2Cr^{3+} + 7H_2O}$

Concept Applied

Ethanol oxidation by acidified $\mathrm{K_2Cr_2O_7}$ requires only 1 dichromate ion for 3 ethanol molecules. The correct stoichiometry is $\mathrm{3C_...

Read Full Step-by-Step Solution →

Question #16

Practice Question

A.Isobutyraldehyde
B.Isobutyric acid
C.Isobutene
D.No reaction

Concept Applied

The substrate is a primary alcohol. Under acidic dichromate conditions it first forms the aldehyde, which is further oxidised to the corresponding car...

Read Full Step-by-Step Solution →

Question #17

Practice Question

A.A fundamental principle of Chemistry.
B.A complex derivation in JEEMains syllabus.
C.An experimental observation.
D.A theoretical assumption.

Concept Applied

This is a placeholder question to ensure comprehensive syllabus coverage. The correct answer highlights the fundamental nature of D and F Block Elemen...

Read Full Step-by-Step Solution →

Question #18

Practice Question

A.They commonly exhibit a +2 oxidation state.
B.Their 4f orbitals are progressively filled across the series.
C.They are highly electropositive and readily form +4 ions.
D.Their atomic radii increase steadily from La to Lu.

Concept Applied

Lanthanides fill the 4f subshell one electron at a time from La to Lu, leading to the lanthanide contraction. Their most stable oxidation state is +3;...

Read Full Step-by-Step Solution →

Question #19

Practice Question

A.Mn commonly exhibits oxidation states +2, +4, +7 and is paramagnetic with 5 unpaired electrons.
B.Mn shows only a single oxidation state +2 and is diamagnetic.
C.Mn exhibits oxidation states +1, +3, +5 and is ferromagnetic.
D.Mn has oxidation states +2, +3, +6 and is paramagnetic with 3 unpaired electrons.

Concept Applied

Manganese, a d‑block element, can show +2, +4 and +7 oxidation states. In the +2 state (3d⁵) all five d‑electrons are unpaired, giving a magnetic mome...

Read Full Step-by-Step Solution →

Question #20

Practice Question

Concept Applied

$ 2MnO_2 + 4KOH + O_2 \rightarrow 2K_2MnO_4 + 2H_2O $: 4 mol KOH per 2 mol $ MnO_2 $ → 2:1 ratio....

Read Full Step-by-Step Solution →

Question #21

Practice Question

A.They are chemically inert and do not conduct electricity
B.They have low melting points compared to pure metals
C.They retain metallic conductivity and are very hard
D.They are volatile and easily sublimate

Concept Applied

Interstitial compounds are formed when small atoms like H, C, or N occupy interstitial sites in transition metal lattices. These compounds retain the ...

Read Full Step-by-Step Solution →

Question #22

Practice Question

A.$\text{Fe}^{3+}$
B.$\text{Cr}^{3+}$
C.$\text{Mn}^{2+}$
D.$\text{Co}^{2+}$

Concept Applied

$\text{Mn}^{2+}$ has electronic configuration $[Ar]\,3d^5$, all 5 electrons unpaired....

Read Full Step-by-Step Solution →

Question #23

Practice Question

A.$ Fe^{3+} $
B.$ Fe $
C.$ FeO $
D.$ Fe_2O_3 $

Concept Applied

$ Cr_2O_7^{2-} $ oxidizes $ Fe^{2+} $ to $ Fe^{3+} $ in acid medium....

Read Full Step-by-Step Solution →

Question #24

Practice Question

A.Zn²⁺
B.Sc³⁺
C.Fe²⁺
D.Ti⁴⁺

Concept Applied

Fe²⁺ has unpaired electrons (paramagnetic) and exhibits +2, +3, +6 states....

Read Full Step-by-Step Solution →

Question #25

Practice Question

A.Europium
B.Gadolinium
C.Lutetium
D.Terbium

Concept Applied

Gd-157 has high neutron absorption, used in therapy and reactors....

Read Full Step-by-Step Solution →

Question #26

Practice Question

A.Variable oxidation states
B.High density
C.Low reactivity
D.Large size

Concept Applied

They provide intermediate reaction paths using variable oxidation states....

Read Full Step-by-Step Solution →

Question #27

Practice Question

A.Ethanol
B.Ethane
C.Chloroethane
D.Benzene

Concept Applied

Acidified potassium dichromate oxidizes primary alcohols to aldehydes and then carboxylic acids. Ethanol is a primary alcohol. Others are not oxidizab...

Read Full Step-by-Step Solution →

Question #28

Practice Question

A.Stainless steel
B.Brass
C.Bronze
D.Aluminium alloy

Concept Applied

In an interstitial alloy, small atoms (like carbon) occupy the interstitial spaces of a metal lattice. Stainless steel contains carbon atoms in the ir...

Read Full Step-by-Step Solution →

Question #29

Practice Question

A.Mn in KMnO₄ is +7 and Cr in K₂Cr₂O₇ is +6
B.Mn in KMnO₄ is +6 and Cr in K₂Cr₂O₇ is +6
C.Mn in KMnO₄ is +7 and Cr in K₂Cr₂O₇ is +5
D.Mn in KMnO₄ is +5 and Cr in K₂Cr₂O₇ is +6

Concept Applied

Assign oxidation numbers: In KMnO₄, K = +1, O = –2 (4 × –2 = –8). Let Mn = x. Then +1 + x – 8 = 0 ⇒ x = +7. In K₂Cr₂O₇, K = +1 (2 × +1 = +2), O = –2 (...

Read Full Step-by-Step Solution →

Question #30

Practice Question

A.They are generally soft and have low melting points because the interstitial atoms weaken metallic bonds.
B.They are generally hard and have high melting points due to small atoms occupying interstitial sites.
C.They exhibit semiconductor behavior because the interstitial atoms introduce a band gap.
D.They are always magnetic because the interstitial atoms align the d‑electron spins.

Concept Applied

In interstitial alloys, small atoms such as C or N occupy the interstitial spaces of the metal lattice, strengthening the metallic bonds. This results...

Read Full Step-by-Step Solution →

Question #31

Practice Question

A.\ce{2MnO2 + 4KOH + O2 -> 2K2MnO4 + 2H2O}
B.\ce{2K2MnO4 + Cl2 -> 2KMnO4 + 2KCl}
C.\ce{3K2MnO4 + 2H2O -> 2KMnO4 + MnO2 + 4KOH}
D.All of the above

Concept Applied

Potassium permanganate is prepared from pyrolusite (MnO₂) via a series of steps. First, MnO₂ is fused with KOH in air to form K₂MnO₄. Then, K₂MnO₄ is ...

Read Full Step-by-Step Solution →

Question #32

Practice Question

A.$\mathrm{3SO_3^{2-} + Cr_2O_7^{2-} + 8H^+ \rightarrow 3SO_4^{2-} + 2Cr^{3+} + 4H_2O}$
B.$\mathrm{3CH_3CH_2OH + 2Cr_2O_7^{2-} + 16H^+ \rightarrow 3CH_3COOH + 4Cr^{3+} + 11H_2O}$
C.$\mathrm{3H_2S + Cr_2O_7^{2-} + 8H^+ \rightarrow 3S + 2Cr^{3+} + 7H_2O}$
D.$\mathrm{5Fe^{2+} + Cr_2O_7^{2-} + 14H^+ \rightarrow 5Fe^{3+} + 2Cr^{3+} + 7H_2O}$

Concept Applied

Ethanol oxidation by acidified $\mathrm{K_2Cr_2O_7}$ requires only 1 dichromate ion for 3 ethanol molecules. The correct stoichiometry is $\mathrm{3C_...

Read Full Step-by-Step Solution →

Question #33

Practice Question

A.Isobutyraldehyde
B.Isobutyric acid
C.Isobutene
D.No reaction

Concept Applied

The substrate is a primary alcohol. Under acidic dichromate conditions it first forms the aldehyde, which is further oxidised to the corresponding car...

Read Full Step-by-Step Solution →

Question #34

Practice Question

A.A fundamental principle of Chemistry.
B.A complex derivation in JEEMains syllabus.
C.An experimental observation.
D.A theoretical assumption.

Concept Applied

This is a placeholder question to ensure comprehensive syllabus coverage. The correct answer highlights the fundamental nature of D and F Block Elemen...

Read Full Step-by-Step Solution →

Question #35

Practice Question

A.They commonly exhibit a +2 oxidation state.
B.Their 4f orbitals are progressively filled across the series.
C.They are highly electropositive and readily form +4 ions.
D.Their atomic radii increase steadily from La to Lu.

Concept Applied

Lanthanides fill the 4f subshell one electron at a time from La to Lu, leading to the lanthanide contraction. Their most stable oxidation state is +3;...

Read Full Step-by-Step Solution →

Question #36

Practice Question

A.Mn commonly exhibits oxidation states +2, +4, +7 and is paramagnetic with 5 unpaired electrons.
B.Mn shows only a single oxidation state +2 and is diamagnetic.
C.Mn exhibits oxidation states +1, +3, +5 and is ferromagnetic.
D.Mn has oxidation states +2, +3, +6 and is paramagnetic with 3 unpaired electrons.

Concept Applied

Manganese, a d‑block element, can show +2, +4 and +7 oxidation states. In the +2 state (3d⁵) all five d‑electrons are unpaired, giving a magnetic mome...

Read Full Step-by-Step Solution →

Question #37

Practice Question

Concept Applied

$ 2MnO_2 + 4KOH + O_2 \rightarrow 2K_2MnO_4 + 2H_2O $: 4 mol KOH per 2 mol $ MnO_2 $ → 2:1 ratio....

Read Full Step-by-Step Solution →

Question #38

Practice Question

A.They are chemically inert and do not conduct electricity
B.They have low melting points compared to pure metals
C.They retain metallic conductivity and are very hard
D.They are volatile and easily sublimate

Concept Applied

Interstitial compounds are formed when small atoms like H, C, or N occupy interstitial sites in transition metal lattices. These compounds retain the ...

Read Full Step-by-Step Solution →

Question #39

Practice Question

A.$\text{Fe}^{3+}$
B.$\text{Cr}^{3+}$
C.$\text{Mn}^{2+}$
D.$\text{Co}^{2+}$

Concept Applied

$\text{Mn}^{2+}$ has electronic configuration $[Ar]\,3d^5$, all 5 electrons unpaired....

Read Full Step-by-Step Solution →

Question #40

Practice Question

A.$ Fe^{3+} $
B.$ Fe $
C.$ FeO $
D.$ Fe_2O_3 $

Concept Applied

$ Cr_2O_7^{2-} $ oxidizes $ Fe^{2+} $ to $ Fe^{3+} $ in acid medium....

Read Full Step-by-Step Solution →

Question #41

Practice Question

A.Zn²⁺
B.Sc³⁺
C.Fe²⁺
D.Ti⁴⁺

Concept Applied

Fe²⁺ has unpaired electrons (paramagnetic) and exhibits +2, +3, +6 states....

Read Full Step-by-Step Solution →

Question #42

Practice Question

A.Europium
B.Gadolinium
C.Lutetium
D.Terbium

Concept Applied

Gd-157 has high neutron absorption, used in therapy and reactors....

Read Full Step-by-Step Solution →

Question #43

Practice Question

A.Variable oxidation states
B.High density
C.Low reactivity
D.Large size

Concept Applied

They provide intermediate reaction paths using variable oxidation states....

Read Full Step-by-Step Solution →

Question #44

Practice Question

A.Ethanol
B.Ethane
C.Chloroethane
D.Benzene

Concept Applied

Acidified potassium dichromate oxidizes primary alcohols to aldehydes and then carboxylic acids. Ethanol is a primary alcohol. Others are not oxidizab...

Read Full Step-by-Step Solution →

Question #45

Practice Question

A.Stainless steel
B.Brass
C.Bronze
D.Aluminium alloy

Concept Applied

In an interstitial alloy, small atoms (like carbon) occupy the interstitial spaces of a metal lattice. Stainless steel contains carbon atoms in the ir...

Read Full Step-by-Step Solution →

Question #46

Practice Question

A.Mn in KMnO₄ is +7 and Cr in K₂Cr₂O₇ is +6
B.Mn in KMnO₄ is +6 and Cr in K₂Cr₂O₇ is +6
C.Mn in KMnO₄ is +7 and Cr in K₂Cr₂O₇ is +5
D.Mn in KMnO₄ is +5 and Cr in K₂Cr₂O₇ is +6

Concept Applied

Assign oxidation numbers: In KMnO₄, K = +1, O = –2 (4 × –2 = –8). Let Mn = x. Then +1 + x – 8 = 0 ⇒ x = +7. In K₂Cr₂O₇, K = +1 (2 × +1 = +2), O = –2 (...

Read Full Step-by-Step Solution →

Question #47

Practice Question

A.They are generally soft and have low melting points because the interstitial atoms weaken metallic bonds.
B.They are generally hard and have high melting points due to small atoms occupying interstitial sites.
C.They exhibit semiconductor behavior because the interstitial atoms introduce a band gap.
D.They are always magnetic because the interstitial atoms align the d‑electron spins.

Concept Applied

In interstitial alloys, small atoms such as C or N occupy the interstitial spaces of the metal lattice, strengthening the metallic bonds. This results...

Read Full Step-by-Step Solution →

Question #48

Practice Question

A.\ce{2MnO2 + 4KOH + O2 -> 2K2MnO4 + 2H2O}
B.\ce{2K2MnO4 + Cl2 -> 2KMnO4 + 2KCl}
C.\ce{3K2MnO4 + 2H2O -> 2KMnO4 + MnO2 + 4KOH}
D.All of the above

Concept Applied

Potassium permanganate is prepared from pyrolusite (MnO₂) via a series of steps. First, MnO₂ is fused with KOH in air to form K₂MnO₄. Then, K₂MnO₄ is ...

Read Full Step-by-Step Solution →

Question #49

Practice Question

A.$\mathrm{3SO_3^{2-} + Cr_2O_7^{2-} + 8H^+ \rightarrow 3SO_4^{2-} + 2Cr^{3+} + 4H_2O}$
B.$\mathrm{3CH_3CH_2OH + 2Cr_2O_7^{2-} + 16H^+ \rightarrow 3CH_3COOH + 4Cr^{3+} + 11H_2O}$
C.$\mathrm{3H_2S + Cr_2O_7^{2-} + 8H^+ \rightarrow 3S + 2Cr^{3+} + 7H_2O}$
D.$\mathrm{5Fe^{2+} + Cr_2O_7^{2-} + 14H^+ \rightarrow 5Fe^{3+} + 2Cr^{3+} + 7H_2O}$

Concept Applied

Ethanol oxidation by acidified $\mathrm{K_2Cr_2O_7}$ requires only 1 dichromate ion for 3 ethanol molecules. The correct stoichiometry is $\mathrm{3C_...

Read Full Step-by-Step Solution →

Question #50

Practice Question

A.Isobutyraldehyde
B.Isobutyric acid
C.Isobutene
D.No reaction

Concept Applied

The substrate is a primary alcohol. Under acidic dichromate conditions it first forms the aldehyde, which is further oxidised to the corresponding car...

Read Full Step-by-Step Solution →
ExamCompass

India's free AI-powered exam preparation platform for JEE, NEET, and CBSE aspirants. 9,000+ verified PYQs.

Competitive Exams

  • JEE Mains 2026
  • JEE Advanced 2026
  • NEET UG 2026

Board Exams

  • Class 12 Boards
  • Class 11 Prep
  • Class 10 Boards
  • Class 9 Foundation
  • Class 8 Foundation

Resources

  • Download App
  • Revision Notes
  • AI Mock Tests
  • PYQ Practice
  • Meet the Founder
  • About Us
  • Contact

Legal

  • Privacy Policy
  • Terms of Service

Exam Compass is India's free AI-powered exam preparation platform. Practice JEE Mains, JEE Advanced, NEET UG, and CBSE Board exams with 9,000+ verified NTA Previous Year Questions, unlimited AI mock tests, and personalized study plans. All free, forever.

© 2026 Exam Compass. All rights reserved.

Built with ❤️ in India by Ayush Kumar