Anhydrous cobalt (II) chloride is blue in colour but on dissolving in water it changes to pink in colour because
- its oxidation state changes
- its magnetic character changes
- its coordination number changes
- in water it shows fluorescence
The Correct Option is C
Solution and Explanation
Top Questions on 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
- Match List-I with List-II.Choose the correct answer from the options given below:
List-I
Alkali MetalList-II
Emission Wavelength
in nm(A) Li (I) 589.2 (B) Na (II) 455.5 (C) Rb (III) 670.8 (D) Cs (IV) 780.0 - JEE Main - 2024
- Chemistry
- d -and f -Block Elements
- A first row transition metal in its +2 oxidation state has a spin-only magnetic moment value of 3.86 BM. The atomic number of the metal is
- JEE Main - 2024
- Chemistry
- d -and f -Block Elements
- The 'Spin only' Magnetic moment for \([Ni(NH_3)_6]^{2+}\) is _____ × \(10^{−1}\) BM. (given = Atomic number of Ni : 28)
- JEE Main - 2024
- Chemistry
- d -and f -Block Elements
- The compound that is white in color is
- JEE Main - 2024
- Chemistry
- d -and f -Block Elements
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