Which of the following arrangements does not represent the correct order of the property stated against it?

• V²⁺ < Cr²⁺<Mn²⁺<Fe²⁺: paramagnetic behaviour

• Ni²⁺ < Co²⁺ < Fe²⁺ < Mn²⁺ ; Ionic size

• Co³⁺ < Fe³⁺< Cr³⁺ < Sc³⁺ : stability in aqueous solution

• Co³⁺ < Fe³⁺< Cr³⁺ < Sc³⁺ : stability in aqueous solution

Iron exhibits + 2 and +3 oxidation states. Which of the following statements about iron is incorrect?

• Ferrous oxide is more basic in nature than the ferric oxide.

• Ferrous compounds are relatively more ionic than the corresponding ferric compounds.

• Ferrous compounds are less volatile than the corresponding ferric compounds.

• Ferrous compounds are less volatile than the corresponding ferric compounds.

The correct order of E°_M2+/M values with negative sign for the four successive elements Cr, Mn, Fe and Co is

• Cr > Mn > Fe > Co

• Mn > Cr > Fe > Co

• Cr > Fe > Mn > Co

• Cr > Fe > Mn > Co

Sodium salt of an organic acid 'X' produces effervescence with conc. H₂SO₄. 'X' reacts with the acidified aqueous CaCl2 solution to give a white precipitate which decolourises acidic solution of KMnO₄. 'X' is

• C₆H₅COONa

• HCOONa

• Na₂C₂O₄

• Na₂C₂O₄

375.

Knowing that the Chemistry of lanthanoids (Ln) is dominated by its +3 oxidation state, which of the following statements in incorrect

• The ionic sizes of Ln (III) decrease in general with increasing atomic number.

• Ln (III) compounds are generally colourless.

• Because of the large size of the Ln (III) ions, the bonding in its compounds is predominantly ionic in character

• Because of the large size of the Ln (III) ions, the bonding in its compounds is predominantly ionic in character

In context with the transition elements, which of the following statements is incorrect?

• In addition to the normal oxidation states, the zero oxidation state is also shown by these elements in complexes.

• In the highest oxidation states, the transition metal shows basic character and form cationic complexes.

• In the highest oxidation states of the first five transition elements (Sc to Mn), all the 4s and 3d electrons are used for bonding.

• In the highest oxidation states of the first five transition elements (Sc to Mn), all the 4s and 3d electrons are used for bonding.

Larger number of oxidation states are exhibited by the actinoids than those by the lanthanoids, the main reason being

• 4f orbitals more diffused than the 5f orbitals

• lesser energy difference between 5f and 6d than between 4f and 5d orbitals

• more energy difference between 5f and 6d than between 4f and 5d orbitals

• more energy difference between 5f and 6d than between 4f and 5d orbitals

Identify the incorrect statement among the following –

• d-Block elements show irregular and erratic chemical properties among themselves

• La and Lu have partially filled d orbitals and no other partially filled orbitals

• The chemistry of various lanthanoids is very similar

• The chemistry of various lanthanoids is very similar

The actinoids exhibits more number of oxidation states in general than the lanthanoids. This is because

• the 5f orbitals are more buried than the 4f orbitals

• there is a similarity between 4f and 5f orbitals in their angular part of the wave function

• the actinoids are more reactive than the lanthanoids

• the actinoids are more reactive than the lanthanoids

The stability of dihalides of Si, Ge, Sn and Pb increases steadily in the sequence

• GeX₂ << SiX₂ << SnX₂<< PbX₂

• SiX₂ << GeX₂ << PbX₂<< SnX₂

• SiX₂ << GeX₂ << SnX₂<< PbX₂

• SiX₂ << GeX₂ << SnX₂<< PbX₂