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The total number of unpaired electrons in the two complexes [Cr(H2O)6]2+ and [Cr(CN)6]4- having octahedral geometry are
    Correct answer is '6'. Can you explain this answer?
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    The total number of unpaired electrons in the two complexes [Cr(H2O)6]...
    In [Cr(H2O)6]2+ chromium have d4 configuration and H2O is a weak field ligand.
    d4 (weak field)

    In [Cr(CN)6]4- chromium have d4 configuration and CN- ion is a strong field ligand. Hence, CN- ion causing pairing of electron. d4 (strong field)

    Hence, total number of unpaired electrons in both the complex are 6.
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    The total number of unpaired electrons in the two complexes [Cr(H2O)6]...
    Solution:

    To find the total number of unpaired electrons in the two complexes, we need to first determine the electronic configuration of the central chromium atom in each complex.

    Electronic configuration of [Cr(H2O)6]2+

    - Chromium is in the +2 oxidation state.
    - The electronic configuration of Cr2+ is [Ar]3d4.
    - In an octahedral complex, the d-orbitals split into two sets of three: the lower energy t2g set and the higher energy eg set.
    - The six water molecules are arranged around the chromium ion in an octahedral geometry.
    - The electrons occupy the t2g set of orbitals first, giving a configuration of [Ar]3d3 t2g^3 eg^0.
    - There are three unpaired electrons in the t2g set.

    Electronic configuration of [Cr(CN)6]4-

    - Chromium is in the +3 oxidation state.
    - The electronic configuration of Cr3+ is [Ar]3d3.
    - The six cyanide ligands are arranged around the chromium ion in an octahedral geometry.
    - The electrons occupy the t2g set of orbitals first, giving a configuration of [Ar]3d3 t2g^3 eg^0.
    - There are three unpaired electrons in the t2g set.

    Total number of unpaired electrons

    - [Cr(H2O)6]2+ has three unpaired electrons in the t2g set.
    - [Cr(CN)6]4- has three unpaired electrons in the t2g set.
    - The total number of unpaired electrons in the two complexes is 3 + 3 = 6.
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    When a transition metal ion (usually) is involved in octahedral complex formation, the five degenerate d-orbitals split into two set of degenerate orbitals (3 + 2). Three degenerate orbitals of lower energy (dxy, dyz, dzx) and a set of degenerate orbitals of higher energy (dx2 y2and dz2). The orbitals with lower energy are called t2gorbitals and those with higher energy are called egorbitals.In octahedral complexes, positive metal ion may be considered to be present at the centre and negative ligands at the corner of a regular octahedron. As lobes ofandlie along the axes, i.e., along the ligands the repulsions are more and so high is the energy. The lobes of the remaining three d-orbitals lie between the axes. i.e., between the ligands. The repulsion between them are less, so lesser the energy. In the octahedral complexes, if metal ion has electrons more than 3 then for pairing them the option are(i) Pairing may start with 4thelectron in t2gorbitals.(ii) Pairing may start normally with 6thelectrons when t2gand egorbitals are singly filled.Q. Select incorrect match for the following complexes.

    When a transition metal ion (usually) is involved in octahedral complex formation, the five degenerate d-orbitals split into two set of degenerate orbitals (3 + 2). Three degenerate orbitals of lower energy (dxy, dyz, dzx) and a set of degenerate orbitals of higher energy (dx2 y2and dz2). The orbitals with lower energy are called t2gorbitals and those with higher energy are called egorbitals.In octahedral complexes, positive metal ion may be considered to be present at the centre and negative ligands at the corner of a regular octahedron. As lobes ofandlie along the axes, i.e., along the ligands the repulsions are more and so high is the energy. The lobes of the remaining three d-orbitals lie between the axes. i.e., between the ligands. The repulsion between them are less, so lesser the energy. In the octahedral complexes, if metal ion has electrons more than 3 then for pairing them the option are(i) Pairing may start with 4thelectron in t2gorbitals.(ii) Pairing may start normally with 6thelectrons when t2gand egorbitals are singly filled.Q. Which of the following electronic arrangement is /are possible for inner orbital oct complex.(I)(II)(III)(IV)Select the correct code

    The total number of unpaired electrons in the two complexes [Cr(H2O)6]2+ and [Cr(CN)6]4-having octahedral geometry areCorrect answer is '6'. Can you explain this answer?
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