What is meant by 'disproportionation'? Give two examples of disproportionation reaction in aqueous solution.
What is meant by 'disproportionation'? Give two examples of disproportionation reaction in aqueous solution.
Solution and Explanation
It is found that sometimes a relatively less stable oxidation state undergoes an oxidation - reduction reaction in which it is simultaneously oxidised and reduced. This is called disproportionation.
For example,
(i) \(3Cr^{3-}_4+8H^+ \rightarrow 2Cr^{2-}_4+Cr^{3+}+4H_2O\)
Cr( V ) Cr ( VI ) Cr ( III )
Cr(V) is oxidized to Cr(VI) and reduced to Cr(III)
(ii) \(3MnO^{2-}_4+4H+\rightarrow2MnO^-_4+MnO_2+2H_2O\)
Mn( VI ) Mn ( VII ) Mn( IV )
Mn (VI) is oxidized to Mn (VII) and reduced to Mn (IV).
Top Questions on d -and f -Block Elements
- Why do transition metals and their compounds act as good catalysts?
- CBSE CLASS XII - 2024
- Chemistry
- d -and f -Block Elements
- What is the cause of contraction in the atomic size of lanthanoids?
- CBSE CLASS XII - 2024
- Chemistry
- d -and f -Block Elements
- Define lanthanoid contraction. How does it affect the atomic radii of the third transition series and the second transition series?
- CBSE CLASS XII - 2024
- Chemistry
- d -and f -Block Elements
- Which of the following elements of the 3d series of transition elements has the lowest \(\Delta_{a} H^\circ\)?
- CBSE CLASS XII - 2024
- Chemistry
- d -and f -Block Elements
- A first row transition metal with the highest enthalpy of atomisation, upon reaction with oxygen at high temperature, forms oxides of formula \( \text{M}_2\text{O}_n \) (where \( n = 3, 4, 5 \)). The 'spin-only' magnetic moment value of the amphoteric oxide from the above oxides is ___ BM (near integer).
(Given atomic number: \( \text{Sc: 21, Ti: 22, V: 23, Cr: 24, Mn: 25, Fe: 26, Co: 27, Ni: 28, Cu: 29, Zn: 30} \))- JEE Main - 2024
- Chemistry
- d -and f -Block Elements
Questions Asked in CBSE CLASS XII exam
- Which fruit has the maximum vitamin A content?
- CBSE CLASS XII - 2024
- Nutrition
- Write the reactions of glucose with
(a) HI
(b)\((CH_3CO_2)O\)- CBSE CLASS XII - 2024
- Biomolecules
- Ankur Sachdeva did his MBA from ITB University. He decided to apply his knowledge of scientific management in the fast food restaurant chain 'Coffee Bean' set up by him. This restaurant was providing burgers, fries, shakes etc, as a part of its menu. Nowadays people are quality conscious, so he was using standardised raw materials, processes, methods, working conditions, machinery etc. The objective was to establish standards of excellence. By doing this he was not only able to reduce the cost but was also able to provide new varieties of burgers, fries and shakes leading to increased turnover. Ankur Sachdeva also believed that there was only one best method to maximise efficiency. As a result he developed best way of grilling burgers, cooking fries and preparing shakes. His main objective was to maximise the satisfaction of customers, which he was able to achieve. Not only to learn the best way of doing a job, but to perform their tasks efficiently, 'Coffee Bean' regularly invests in training and development programmes to equip employees with the necessary skill and knowledge. 'Coffee Bean' believed that efficient employees will produce more and earn more. This will ensure their greatest efficiency and prosperity for both company and workers. The above case highlights the use of Scientific principles and techniques by 'Coffee Bean'. Explain any one such principle and two techniques.
- CBSE CLASS XII - 2024
- Marketing Management
- Preeti started her own cooking channel on 'Youtube Mood Art'. As her subscribers increased, she was not in a position to manage everything on her own. She hired Rahul and Riya to help her with filming editing, lighting and content research. She granted authority to them to operate within prescribed limits. She was thus, able to use her time on high priority activities like developing new recipes and content development etc. As a result, Rahul and Riya were given opportunities to develop and exercise initiative. Preeti was now able to focus on objectives and meet the target of achieving a subscriber base of one million in six months.
(a) Identify the concept of management used by Preeti.
(b) Explain any five points of importance of the concept identified in .- CBSE CLASS XII - 2024
- Organising
- Explain the following types of plans:
(b) Strategy
(ii) Method
(iii) Budget- CBSE CLASS XII - 2024
- Principles of Management
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