The d-and f-Block Elements

CBSE Class 12 Chemistry · every board question from this chapter, 2022–2026 · 46 of them repeated across years

• Identify the correct statement:2026
• Which property of transition metals enables them to form alloys?2026
• Which of the following d-orbitals experience more repulsion in the crystal field splitting of tetrahedral complex?2026
• Which of the following d-orbitals experience more repulsion in the crystal field splitting of octahedral complex?2026asked 2×
• Which of the following transition metals has lowest enthalpy of atomisation?2026
• Electronic configuration of chromium is:2026
• Which of the following is not a transition metal?2026
• Electronic configuration of chromium is:2026asked 2×
• Actinoids show larger number of oxidation states:2026asked 3×
• Manganate ion is paramagnetic due to the presence of:2026
• Which of the following transition metals shows +1 and +2 oxidation states?2026
• In aqueous solution, Cr 2 O 7^2- ion converts to which of the following in alkaline medium?2026
• Which of the following transition metals shows +1 and +2 oxidation states?2026asked 2×
• In aqueous acidified solution, CrO 4^2- ion converts to which of the following?2026
• Assertion: Separation of Zr and Hf is difficult. Reason (R): Zr and Hf have almost identical atomic and ionic radii due to…2026
• Assertion: Separation of Zr and Hf is difficult. Reason (R): Because Zr and Hf lie in the same group of the periodic table.2026
• Assertion: Actinoids show irregularities in their electronic configurations. Reason (R): Due to varying stabilities of f^0, f^7…2026
• Assertion: Zinc, cadmium and mercury are not considered as transition elements. Reason (R): These elements have completely filled…2026asked 3×
• Assertion: Highest oxidation state of Mn is +7 in first series of transition elements. Reason (R): Transition metals exhibit…2026asked 3×
• Assertion: Actinoids show irregularities in their electronic configurations. Reason (R): In actinoids 5f, 6d and 7s orbitals are…2026
• Assertion: E Sc^3+ / Sc^2+^O has low value. Reason (R): Because of the stability of Sc^3+ ion which has a noble gas configuration.2026
• Why second ionization enthalpies of chromium and copper are exceptionally higher than those of their neighbouring elements? 1 + 1…2026
• Why is third ionization enthalpy of manganese very high? 1 + 1 Why Zn, Cd and Hg are not regarded as transition elements?2026
• First ionization enthalpy of Cr is lower than that of Zn. Why? 1 + 1 Mention any one property of the transition elements which…2026
• Complete and balance the following equations: 2+1 (i) 4 FeCr 2 O 4+8 Na 2 CO 3+7 O 2 → (ii) 5 Fe^2++MnO 4^-+8 H^+ → Explain why…2026
• Complete and balance the following equations: (i) 2 KMnO 4 513 K (ii) Na 2 Cr 2 O 7+2 KCl → Why is it difficult to separate…2026
• Complete and balance the following equations: (i) 2 Na 2 CrO 4+2 H^+ → (ii) 5 S^2-+2 MnO 4^-+16 H^+ → Why is chemistry of…2026
• (i) Describe giving reason which one of the following pairs has the property indicated: (I) Fe or Cu - higher melting point (II)…2026asked 3×
• (i) Account for the following: (I) MnO is basic while Mn 2 O 7 is acidic. (II) Iron has higher enthalpy of atomization than that…2026asked 3×
• (i) (I) Why do transition metals show variable oxidation states? (II) Out of Mn^2+ and Ti^2+ which will be more paramagnetic and…2026asked 3×
• (i) From the given data of E^° values, answer the following questions: (I) Why E M^2+ / M^° show irregular trend in the above…2026asked 3×
• With increase in atomic number, the melting point of transition metals:2025
• Which of the following transition metal ion is not coloured?2025
• Among the following outermost electronic configurations of transition metals, which one shows the highest oxidation state?2025
• Out of Fe^3+, Sc^3+, Cr^3+ and Co^3+ ions, the one which is colourless in aqueous solution is:2025
• Out of Ti^3+, Cr^3+, Fe^2+ and Ni^2+ ions, the one which is the most stable ion in aqueous solution is:2025
• The magnetic moment is associated with its spin angular momentum and orbital angular momentum. Spin only magnetic moment value of…2025asked 3×
• The element having [Ar] 3 d^10 4 s^1 electronic configuration is2025asked 3×
• Acidified KMnO 4 oxidises sulphite to2025asked 3×
• Which of the following transition metals has the highest melting point?2025
• Which of the following is the softest metal?2025
• Which of the following does not show variable oxidation state?2025
• The diamagnetic species is:2025asked 3×
• Which of the following properties of transition metals enables them to behave as catalysts?2025
• In which of the following groups are both ions coloured in aqueous solution? I. Cu^+ II. Ti^4+ III. Co^2+ IV. Fe^2+ [Atomic…2025asked 3×
• Out of Ti^3+, Cr^3+, Mn^2+ and Ni^2+ ions, the one which has the highest magnetic moment is:2025
• Assertion: Cuprous salts are diamagnetic. Reason (R): In cuprous ion, 3d-orbitals are partially filled.2025
• Assertion: Actinoids show wide range of oxidation states. Reason (R): Actinoids are radioactive in nature.2025asked 2×
• Assertion: Actinoid contraction is greater from element to element than lanthanoid contraction. Reason (R): Actinoids show wide…2025
• Assertion: Actinoids show wide range of oxidation states. Reason (R): This is due to comparable energies of 5f, 6d and 7s…2025
• Assertion: Cuprous salts are diamagnetic. Reason (R): Cuprous ion has completely filled 3d-orbitals.2025asked 2×
• Assertion: Actinoids show irregularities in their electronic configurations. Reason (R): This is due to varying stability of f^0,…2025
• Assertion: Actinoids show irregularities in their electronic configurations. Reason (R): Actinoids are radioactive in nature.2025
• Assertion: First ionisation enthalpy of Cr is lower than that of Zn. Reason (R): Zinc is a non-transition element.2025
• Complete and balance the following chemical equations: 2 MnO 4^-(aq)+10 I^-(aq)+16 H^+(aq) → Cr 2 O 7^2-(aq)+6 Fe^2+(aq)+14…2025
• When FeCr 2 O 4 is fused with Na 2 CO 3 in the presence of air it gives a yellow solution of compound. Compound on acidification…2025
• When FeCr 2 O 4 is fused with Na 2 CO 3 in the presence of air it gives a yellow solution of compound. Compound on acidification…2025
• Examine the following observations: 2 × 1 Transition elements generally form coloured compounds. Zinc is not regarded as a…2025
• Of the d^4 species, Cr^2+ is strongly reducing while Mn^3+ is strongly oxidising. Why? Write two consequences of lanthanoid…2025
• E (Mn^2+ / Mn)^° is -1.18 V. Why is this value highly negative in comparison to neighbouring d-block elements? What is lanthanoid…2025
• Complete and balance the following chemical equations: 3 × 1 MnO 4^-+C 2 O 4^2-+H^+ → KMnO 4 [513 K] Heat Cr 2 O 7^2-+H 2 S+H^+ →2025
• The elements of 3d transition series are given as: Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn Answer the following: Copper has…2025asked 3×
• Give explanation for each of the following observations: With the same d-orbital configuration (d^4), Mn^3+ ion is an oxidising…2025asked 3×
• (i) Account for the following: (I) Orange colour of Cr 2 O 7^2- ion changes to yellow when treated with an alkali. (II) Zn, Cd…2025asked 3×
• (i) When pyrolusite ore is fused with KOH, in presence of air, a dark green coloured product 'A' is obtained which changes to…2025asked 3×
• (i) Account for the following: (I) The E Mn^2+ / Mn^° value for manganese is highly negative, whereas E Mn^3+ / Mn^2+^° is highly…2025asked 3×
• The most stable oxidation state of Iron is:2024
• Which one of the following first row transition elements is expected to have the highest third ionization enthalpy?2024
• The correct order for the increasing oxidizing power in 3d series of transition elements is:2024
• Which of the following does not show variable oxidation states?2024
• When MnO 2 is fused with KOH in air, it gives:2024
• Which of the following is diamagnetic in nature?2024
• Which of the following elements of 3d series of transition elements has the lowest Δ a H^0?2024
• Transition elements form alloys easily because they have:2024
• Transition metals are known to make interstitial compounds. Formation of interstitial compounds makes the transition metal2024asked 3×
• From the elements of 3d series given below, which element shows the maximum number of oxidation states?2024asked 3×
• The general electronic configuration of d-block elements is:2024asked 3×
• Assertion: Zr and Hf are of almost similar atomic radii. Reason (R): This is due to Lanthanoid contraction.2024asked 3×
• Assertion: Separation of Zr and Hf is difficult. Reason (R): Zr and Hf have similar radii due to lanthanoid contraction.2024
• Assertion: Transition metals have high enthalpy of atomization. Reason (R): This is because transition metals have low melting…2024
• Assertion: Separation of Zr and Hf is difficult. Reason (R): Zr and Hf are radioactive.2024
• Complete and balance the following chemical equations: KMnO 4 heat 2 MnO 4^-+5 C 2 O 4^2-+16 H^+ →2024
• What is lanthanoid contraction? Actinoid contraction is greater from element to element than lanthanoid contraction. Why? OR Why…2024asked 3×
• Complete and balance the following chemical equations: 3 MnO 4^2-+4 H^+ → Cr 2 O 7^2-+14 H^++6 Fe^2+ →2024
• The involvement of (n-1) d electrons in the behaviour of transition elements impart certain distinct characteristics to these…2024asked 3×
• Transition metals have incomplete d-subshell either in neutral atom or in their ions. The presence of partly filled d-orbitals in…2024asked 3×
• Attempt any five of the following: Why Zinc is not regarded as a transition element? What is Lanthanoid contraction? Why is first…2024asked 3×
• Attempt any five of the following: 1 × 5 Ce(III) is easily oxidised to Ce(IV). Comment. E^°(Mn^2+ / Mn) is -1.18 V. Why is this…2024asked 3×
• (i) Account for the following: (1) The melting and boiling points of Zn, Cd and Hg are low. (2) Of the d^4 species, Cr^2+ is…2024asked 3×
• Lanthanoid contraction is due to increase in:2023
• The oxidation state of Fe in [Fe(CO) 5] is2023
• Which of the following Cu^2+ halide is not known?2023
• The interstitial compounds of transition metals are2023
• The ions of metals of Group 12 (Zn, Cd and Hg) have completely filled d orbitals and so they:2023
• Which property of transition metals enables them to behave as catalysts?2023asked 3×
• In the two tetrahedral structures of dichromate ion2023
• Which of the following ions has the electronic configuration 3 d^6? (Atomic number: Mn=25, Co=27, Ni=28 )2023
• The most common and stable oxidation state of a Lanthanoid is:2023asked 3×
• Among the following outermost configurations of transition metals which one shows the highest oxidation state?2023
• KMnO 4 acts as an oxidising agent in alkaline medium. When alkaline KMnO 4 is treated with KI, iodide ion is oxidised to:2023
• Which of the following transition metals does not show variable oxidation state?2023
• Which of the following ions has the maximum number of unpaired d-electrons?2023
• Which of the following characteristics of transition metals is associated with their catalytic activity?2023
• In which of the following does the central atom exhibit an oxidation state of+3?2023
• Which one among the following metals of 3d series has the lowest melting point?2023
• In which of the following does the central atom exhibit an oxidation state of +4?2023
• Assertion: Transition metals show their highest oxidation state with oxygen. Reason (R): The ability of oxygen to form multiple…2023asked 2×
• Assertion: Copper is a non-transition element. Reason (R): Copper has completely filled d-orbitals in its ground state.2023
• Assertion: Zr and Hf have almost identical radii. Reason (R): Both Zr and Hf exhibit similar properties.2023
• Assertion: Transition metals have high enthalpy of atomisation. Reason (R): Greater number of unpaired electrons in transition…2023
• Assertion: Manganese shows the highest oxidation state of +7 in 3d series. Reason (R): Transition metals show variable oxidation…2023
• Assertion: Fe^2+ acts as a reducing agent. Reason (R): Fe^3+ state is stable due to 3 d^5 configuration.2023
• Assertion: Zinc is not regarded as a transition element. Reason (R): In zinc, 3d orbitals are completely filled in its ground…2023asked 3×
• How would you account for: The E^° value for the Mn^3+ / Mn^2+ couple is much more positive than that for Cr^3+ / Cr^2+ couple or…2023
• (i) Account for the following: (1) Transition metals form complex compounds. (2) The E Mn^2+ / Mn^° value for manganese is highly…2023asked 3×
• (I) Account for the following: 3 + 2 (i) E^o value for Mn^3+ / Mn^2+ couple is much more positive than that for Cr^3+ / Cr^2+.…2023asked 3×
• (i) Account for the following: (1) Zn^2+ salts are colourless while Ni^2+ salts are coloured. (2) Cr^2+ is a strong reducing…2023asked 3×
• (i) In 3d series, which transition element has positive E M^2+ / M value and why? (ii) Name a member of lanthanide series which…2023
• Assign reason for each of the following: (i) Manganese exhibits the highest oxidation state of+7 among the 3d series of…2023asked 2×
• A transition element X has electronic configuration [Ar] 4 s^2 3 d^3. Predict its likely oxidation states. 1+1+3=5 Complete the…2023
• Write the number of unpaired electrons in Cr^3+. (Atomic number of Cr=24 ) Complete the reaction mentioning all the products…2023
• Why is chemistry of actinoids complicated as compared to lanthanoids? Complete the following reaction and justify that it is a…2023
• Account for the following: (i) Cr^2+ is a strong reducing agent. (ii) Ti^3+ is coloured whereas Sc^3+ is colourless in aqueous…2022
• Account for the following: (i) Cu^2+ salts are coloured while Zn^2+ salts are white. (ii) E^° value for the Mn^3+ / Mn^2+ couple…2022
• (i) Why are melting points of transition metals high? (ii) Why the transition metals generally form coloured compounds? (iii) Why…2022
• Following ions of 3d-transition series are given: Ti^4+, V^3+, Cr^3+, Mn^3+ (Atomic number: Ti=22, V=23, Cr=24, Mn=25 ) Identify…2022
• From the given E^ values of the first row transition elements, answer the following questions: (i) Why is E Mn^2+ / Mn^ value…2022asked 3×
• (i) Which ion amongst the following is colourless and why? Ti^4+, Cr^3+, V^3+ (Atomic number of Ti=22, Cr=24, V=23 ) (ii) Why is…2022asked 3×
• What is Lanthanoid contraction? What is the cause of Lanthanoid contraction? Write two consequences of Lanthanoid contraction.2022
• Write any two consequences of Lanthanoid Contraction. Name the element of 3d series which exhibits the largest number of…2022asked 3×
• Give reasons for the following statements: Copper does not displace hydrogen from acids. Transition metals and most of their…2022
• Give reasons for the following statements: Scandium (Z=21) is a transition element but Zn(Z=30) is not. [Ti(H 2 O)]^3+ is…2022
• Give reasons for the following statements: Transition elements and their compounds act as good catalysts. E^o(Mn^2+ / Mn) value…2022
• Account for the following: (i) Zr and Hf have almost similar atomic radii. (ii) Transition metals show variable oxidation states.…2022
• Following ions of 3d transition series are given: V^3+, Cr^2+, Cu^+, Fe^2+, (Atomic number: V=23, Cr=24, Cu=29, Fe=26 ) Identify…2022
• Account for the following: (i) Transition elements have higher enthalpies of atomisation. (ii) Separation of a mixture of…2022
• Define transition metals. Why Zn, Cd and Hg are not called transition metals? How is the variability in oxidation states of…2022asked 2×
• Following ions of 3d transition series are given: Ti^2+, Fe^2+, Cu^2+, Zn^2+ (Atomic number: Ti=22, Fe=26, Cu=29, Zn=30 )…2022
• (i) Silver atom has completely filled d-orbitals in its ground state, it is still considered to be a transition element. Justify…2022asked 3×
• Account for the following: (i) Transition metals and their compounds show catalytic activities. (ii) Zn, Cd and Hg are…2022asked 3×
• Account for the following: (i) Transition metals and their compounds act as good catalysts. (ii) Eu^2+ is a strong reducing…2022

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