d- and f-Block Elements

Although +3 oxidation state is most common in lanthanoids, cerium still shows +4 oxidation state because :

1. After losing one more electron, it acquires 4f14 electronic configuration.
2. Its nearest inert gas is Radon.
3. After losing one more electron, it acquires 4f0 electronic configuration.
4. Its atomic number is 61.

The calculated 'spin-only' magnetic moment of Ti2+ (3d2) is :

1. 3.87 BM
2. 4.90 BM
3. 2.84 BM
4. 5.92 BM

Match List I with List II :

1. A-III, B-IV, C-I, D-II
2. A-III, B-I, C-IV, D-II
3. A-II, B-I, C-IV, D-III
4. A-IV, B-I, C-III, D-II

The lanthanide ion having four unpaired electrons is (Given : Atomic numbers of Ce = 58, Nd = 60, Tb = 65 and Ho = 67)

1. Ho3+
2. Nd3+
3. Ce3+
4. Tb3+

The green paramagnetic species formed by heating KMnO4 at 513 K is

1. KO2
2. K2MnO4
3. Mn3O4
4. MnO

Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R. In light of the above statements, choose the most appropriate answer from the options given below:

1. A is not correct but R is correct
2. Both A and R are correct and R is the correct explanation of A
3. Both A and R are correct and R is NOT the correct explanation of A
4. A is correct but R is not correct.

Match List - I with List - II. Choose the correct answer from the options given below :

1. A-I, B-II, C-III, D-IV
2. A-I, B-IV, C-III, D-II
3. A-I, B-II, C-IV, D-III
4. A-II, B-III, C-I, D-IV

Given below are two statements : In the light of the above statements, choose the correct answer from the options given below :

1. Statement I is true but Statement II is false
2. Statement I is false but Statement II is true
3. Both Statement I and Statement II are true
4. Both Statement I and Statement II are false

'Spin only' magnetic moment is same for which of the following ions? Choose the most appropriate answer from the options given below.

1. B and D only
2. A and E only
3. B and C only
4. A and D only

The E value for the Mn3+/Mn2+ couple is more positive than that of Cr3+/Cr2+ or Fe3+/Fe2+ due to change of

1. d5 to d4 configuration
2. d5 to d2 configuration
3. d4 to d5 configuration
4. d3 to d5 configuration

The pair of lanthanoid ions which are diamagnetic is

1. Ce4+ and Yb2+
2. Ce3+ and Eu2+
3. Gd3+ and Eu3+
4. Pm3+ and Sm3+

Which of the following pairs of ions will have same spin only magnetic moment values within the pair? Choose the correct answer from the options given below :

1. C and D only
2. A and D only
3. A and B only
4. B and C only

Which of the following set of ions act as oxidising agents?

1. Ce4+ and Tb4+
2. La3+ and Lu3+
3. Eu2+ and Yb2+
4. Eu2+ and Tb4+

The UV-visible absorption bands in the spectra of lanthanoid ions are 'X', probably because of the excitation of electrons involving 'Y'. The 'X' and 'Y', respectively, are :

1. Broad and f orbitals
2. Narrow and f orbitals
3. Broad and d and f orbitals
4. Narrow and d and f orbitals

The oxidation states not shown by Mn in given reaction are : 3MnO42- + 4H+ 2MnO4- + MnO2 + 2H2O Choose the most appropriate answer from the options given below :

1. D and E only
2. B and D only
3. A and B only
4. B and E only

The stability of Cu2+ is more than Cu+ salts in aqueous solution due to -

1. enthalpy of atomization.
2. hydration energy.
3. second ionisation enthalpy.
4. first ionisation enthalpy.

Which of the following statements are INCORRECT? Choose the correct answer from the options given below:

1. B and D only
2. C and D only
3. B and C only
4. A and E only

Gadolinium has a low value of third ionisation enthalpy because of

1. small size
2. high exchange enthalpy
3. high electronegativity
4. high basic character

In the neutral or faintly alkaline medium, KMnO4 oxidises iodide into iodate. The change in oxidation state of manganese in this reaction is from

1. +7 to +4
2. +6 to +4
3. +7 to +3
4. +6 to +5

Decrease in size from left to right in actinoid series is greater and gradual than that in lanthanoid series due to

1. 5f orbitals have greater shielding effect
2. 4f orbitals are penultimate
3. 4f orbitals have greater shielding effect
4. 5f orbitals have poor shielding effect

Given below are two statements : In the light of the above statements, choose the most appropriate answer from the options given below :

1. Statement I is incorrect but Statement II is correct
2. Both Statement I and Statement II are correct
3. Both Statement I and Statement II are incorrect
4. Statement I is correct but Statement II is incorrect

The incorrect statement among the following is :

1. Actinoids are highly reactive metals, especially when finely divided.
2. Actinoid contraction is greater for element to element than lanthanoid contraction.
3. Most of the trivalent Lanthanoid ions are colorless in the solid state.
4. Lanthanoids are good conductors of heat and electricity.

Zr (Z = 40) and Hf (Z = 72) have similar atomic and ionic radii because of :

1. Having similar chemical properties
2. Belonging to same group
3. Diagonal relationship
4. Lanthanoid contraction

The calculated spin only magnetic moment of Cr2+ ion is?

1. 4.90 BM
2. 5.92 BM
3. 2.84 BM
4. 3.87 BM

Identify the incorrect statement.

1. The transition metals and their compounds are known for their catalytic activity due to their ability to adopt multiple oxidation states and to form complexes.
2. Interstitial compounds are those that are formed when small atoms like H, C or N are trapped inside the crystal lattices of metals.
3. The oxidation states of chromium in CrO42- and Cr2O72- are not the same.
4. Cr2+ (d4) is a stronger reducing agent than Fe2+ (d6) in water.

The manganate and permanganate ions are tetrahedral due to :

1. The -bonding involves overlap of p-orbitals of oxygen with p-orbitals of manganese
2. The -bonding involves overlap of d-orbitals of oxygen with d-orbitals of manganese
3. The -bonding involves overlap of p-orbitals of oxygen with d-orbitals of manganese
4. There is no -bonding

Which one of the following ions exhibits d-d transition and paramagnetism as well?

1. CrO42-
2. Cr2O72-
3. MnO4-
4. MnO42-

The reason for greater range of oxidation states in actinoids is attributed to

1. actinoid contraction
2. 5f, 6d and 7s levels having comparable energies
3. 4f and 5d levels being close in energies
4. the radioactive nature of actinoids.

Which one of the following statements is correct when SO2 is passed through acidified K2Cr2O7 solution?

1. SO2 is reduced.
2. Green Cr2(SO4)3 is formed.
3. The solution turns blue.
4. The solution is decolourised.

The electronic configuration of Eu (Atomic No. 63), Gd (Atomic No. 64) and Tb (Atomic No. 65) are

1. [Xe]4f6 5d1 6s2, [Xe]4f7 5d1 6s2 and [Xe]4f8 5d1 6s2
2. [Xe]4f7 6s2, [Xe]4f7 5d1 6s2 and [Xe]4f9 6s2
3. [Xe]4f7 6s2, [Xe]4f8 6s2 and [Xe]4f8 5d1 6s2
4. [Xe]4f6 5d1 6s2, [Xe]4f7 5d1 6s2 and [Xe]4f9 6s2