Give examples and suggest reasons for the following features of the transition metal chemistry:
- The lowest oxide of transition metal is basic, the highest is amphoteric/acidic.
- A transition metal exhibits highest oxidation state in oxides and fluorides.
- The highest oxidation state is exhibited in oxoanions of a metal.
Give examples and suggest reasons for the following features of the transition metal chemistry:
- The lowest oxide of transition metal is basic, the highest is amphoteric/acidic.
- A transition metal exhibits highest oxidation state in oxides and fluorides.
- The highest oxidation state is exhibited in oxoanions of a metal.
Solution and Explanation
(i) In the case of a lower oxide of a transition metal, the metal atom has a low oxidation state. This means that some of the valence electrons of the metal atom are not involved in bonding. As a result, it can donate electrons and behave as a base. On the other hand, in the case of a higher oxide of a transition metal, the metal atom has a high oxidation state. This means that the valence electrons are involved in bonding and so, they are unavailable. There is also a high effective nuclear charge.
As a result, it can accept electrons and behave as an acid.
VII
For example, \(Mn^{11}O\) is basic and \(Mn_2O7\) is acidic.
(ii) Oxygen and fluorine act as strong oxidising agents because of their high electronegativities and small sizes. Hence, they bring out the highest oxidation states from the transition metals. In other words, a transition metal exhibits higher oxidation states in oxides and fluorides. For example, in OsF6 and V2O5, the oxidation states of Os and V are +6 and +5 respectively.
(iii) Oxygen is a strong oxidising agent due to its high electronegativity and small size. So, oxo-anions of a metal
have the highest oxidation state. For example, in \(MnO^-_4\), the oxidation state of Mn is +7.
Top Questions on d -and f -Block Elements
- What happens when acidic solution of potassium permanganate is allowed to stand for sometime ? Give the equation involved. What is this type of reaction called ?
- CBSE CLASS XII - 2026
- Chemistry
- d -and f -Block Elements
- Why Cr has higher melting point than Mn ?
- CBSE CLASS XII - 2026
- Chemistry
- d -and f -Block Elements
- Why transition metals act as good catalyst ?
- CBSE CLASS XII - 2026
- Chemistry
- d -and f -Block Elements
- Name a member of the lanthanoid series
(I) which exhibits +4 oxidation state
(II) which exhibits +2 oxidation state.
- CBSE CLASS XII - 2026
- Chemistry
- d -and f -Block Elements
- Write the ionic equations for the oxidising action of potassium permanganate for its reaction with \(I^-\) in both acidic and alkaline solutions.
- CBSE CLASS XII - 2026
- Chemistry
- d -and f -Block Elements
Questions Asked in CBSE CLASS XII exam
- Find the general solution of the differential equation \[ y\log y\,\frac{dx}{dy}+x=\frac{2}{y}. \]
- CBSE CLASS XII - 2026
- Differential Equations
- A square loop of side 0.50 m is placed in a uniform magnetic field of 0.4 T perpendicular to the plane of the loop. The loop is rotated through an angle of 60° in 0.2 s. The value of emf induced in the loop will be:
- CBSE CLASS XII - 2026
- Electromagnetic induction
A racing track is built around an elliptical ground whose equation is given by \[ 9x^2 + 16y^2 = 144 \] The width of the track is \(3\) m as shown. Based on the given information answer the following:
(i) Express \(y\) as a function of \(x\) from the given equation of ellipse.
(ii) Integrate the function obtained in (i) with respect to \(x\).
(iii)(a) Find the area of the region enclosed within the elliptical ground excluding the track using integration.
OR
(iii)(b) Write the coordinates of the points \(P\) and \(Q\) where the outer edge of the track cuts \(x\)-axis and \(y\)-axis in first quadrant and find the area of triangle formed by points \(P,O,Q\).
- CBSE CLASS XII - 2026
- Integration
- Consider a cylindrical conductor of length \( l \) and area of cross-section \( A \). Current \( I \) is maintained in the conductor and electrons drift with velocity \( \vec{v}_d \, (|\vec{v}_d| = \frac{eE}{m} \tau) \), where symbols have their usual meanings. Show that the conductivity of the material of the conductor is given by \[ \sigma = \frac{n e^2 \tau}{m}. \]
- CBSE CLASS XII - 2026
- Current Density
- The painting Hazrat Nizamuddin Auliya and Amir Khusro belongs to which sub-school of Deccan Miniature?
- CBSE CLASS XII - 2026
- Indian Miniature Paintings and Museums
Concepts Used:
D and F Block Elements
The d-block elements are placed in groups 3-12 and F-block elements with 4f and 5f orbital filled progressively. The general electronic configuration of d block elements and f- block elements are (n-1) d 1-10 ns 1-2 and (n-2) f 1-14 (n-1) d1 ns2 respectively. They are commonly known as transition elements because they exhibit multiple oxidation states because of the d-d transition which is possible by the availability of vacant d orbitals in these elements.
They have variable Oxidation States as well as are good catalysts because they provide a large surface area for the absorption of reaction. They show variable oxidation states to form intermediate with reactants easily. They are mostly lanthanoids and show lanthanoid contraction. Since differentiating electrons enter in an anti-penultimate f subshell. Therefore, these elements are also called inner transition elements.
Read More: The d and f block elements