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Payal posted an Question
July 10, 2020 • 05:43 am 30 points
  • IIT JAM
  • Chemistry (CY)

The red colour of uby is due to (a) d-d transition of cr* ion in cr,o, lattice (c) ligand to metal charge transfer transition the ion(s) that exhibit only charg

Please solve question no.4,5&6. The red colour of uby is due to (a) d-d transition of Cr* ion in Cr,O, lattice (c) ligand to metal charge transfer transition The ion(s) that exhibit only charge transfer bond in the absorption spectra (UV-visible region) is(are) (a) [Cr(C,O),P The total number of isomers possible for the molecule [Co(NH) CINO,)]* is_ 4. (b) d-d transition of Cr* ion in AilO, lattice (d) metal to metal charge transfer transition 5. (b) [CrOJ )ReoJF ()[NiOP O.

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    Priyanshu kumar

    hope this helps😊🙏

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    Thank you very much ☺️

    eduncle-logo-app

    welcome...and please accept it if it helps😊🙏

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    Lingareddy 1

    In order to understand the the color study of Ruby we need to know the structure of Ruby(corundum). A crystal of pure Al2O3 is known as corundum, and as colorless sapphire when in gem-quality form. In this material, six oxygen atoms surround each aluminum atom in the form of a slightly distorted octahedron. The three oxygen atoms above the aluminum are closer to each other than the three oxygen atoms below, and the aluminum atom is a little lower than halfway down. Half of the aluminum atoms have this arrangement, and the other half have an inverted arrangement. If this arrangement is viewed in terms of ionic bonds, then the positive aluminum ion is surrounded by six negative charges (oxygen ions). Each aluminum atom donates three electrons to become Al3+ and has no unoccupied energy levels, while each oxygen atom receives two electrons, ensuring that it has no unoccupied energy levels. Therefore, two aluminum atoms donate a total of six electrons, and three oxygen atoms receive a total of six electrons, to produce Al2O3. They produce an electrostatic field around the aluminum ions, called a crystal field. Since the bond is not purely ionic, but has some covalent nature, it can also be treated as a ligand field. So, not only the electric charges, but also the specific bonding characteristics of the ligands (ions or molecules surrounding the central atom or ion) are included. The symmetry and strength of the ligand field both need to be considered when predicting the effects of the ligands. The color of Ruby is due to the presence of chromium. In pure corundum, all electrons are paired and there is no absorption of light. Once one out of every hundred aluminum atoms is replaced by chromium atoms, negatively charged oxygen ions surround the aluminum ion (which has donated 3 electrons), so a chromium atom must donate three electrons to become Cr3+ , replacing Al3+, in order for the charge to remain the same. In Al3+ there are no partially filled energy levels or orbitals. However, in Cr3+there are partially filled energy levels or orbitals. It is these electrons that can be excited and that cause absorption of certain wavelengths of light, resulting in color.

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    Thank you sir

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    Priyanshu kumar

    for ques 5 B is right and C is right as Cr+6 and Re+7 have empty orbital

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    Priyanshu kumar best-answer

    due to its d-d transition in Al203 lattice which emits red colour

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