All Exams Test series for 1 year @ ₹349 only
Question

The total number of unpaired electrons present in the $\text{d}^{3}$, $\text{d}^{4}$ (low spin) $\text{d}^{5}$ (high spin), $\text{d}^{6}$ (high spin) and $\text{d}^{7}$ (low spin) octahedral complex systems is ___________.

Octahedral Complex Unpaired Electrons Calculation

In octahedral complexes, the d-orbitals split into a lower energy set ($t_{2g}$) and a higher energy set ($e_g$). The number of unpaired electrons depends on the total number of d-electrons (the $\text{d}^{n}$ configuration) and the spin state, determined by ligand field strength.

Calculating Unpaired Electrons for Each System

We calculate the unpaired electrons for each specified configuration:

1. $\text{d}^{3}$ System

  • Configuration in octahedral field: $t_{2g}^3$.
  • Electrons fill the $t_{2g}$ orbitals singly as per Hund's rule.
  • Number of unpaired electrons = 3.

2. $\text{d}^{4}$ (low spin) System

  • Low spin indicates strong ligand field, favouring pairing.
  • Configuration: $t_{2g}^4$.
  • The first 3 electrons fill $t_{2g}$ singly. The 4th electron pairs up in a $t_{2g}$ orbital.
  • Number of unpaired electrons = 2.

3. $\text{d}^{5}$ (high spin) System

  • High spin indicates weak ligand field, favouring maximum unpaired electrons.
  • Configuration: $t_{2g}^3 e_g^2$.
  • All 5 electrons occupy orbitals singly.
  • Number of unpaired electrons = 5.

4. $\text{d}^{6}$ (high spin) System

  • High spin configuration.
  • Configuration: $t_{2g}^4 e_g^2$.
  • In $t_{2g}^4$, there are 2 unpaired electrons (3 singles + 1 pair).
  • In $e_g^2$, there are 2 unpaired electrons.
  • Total unpaired electrons = 2 + 2 = 4.

5. $\text{d}^{7}$ (low spin) System

  • Low spin configuration.
  • Configuration: $t_{2g}^6 e_g^1$.
  • The $t_{2g}$ orbitals are fully paired ($t_{2g}^6$), contributing 0 unpaired electrons.
  • The $e_g$ orbitals have 1 electron ($e_g^1$).
  • Total unpaired electrons = 0 + 1 = 1.

Total Unpaired Electrons Summation

To find the total number of unpaired electrons, we sum the values calculated for each system:

Total = (Unpaired $\text{d}^{3}$) + (Unpaired $\text{d}^{4}$ low spin) + (Unpaired $\text{d}^{5}$ high spin) + (Unpaired $\text{d}^{6}$ high spin) + (Unpaired $\text{d}^{7}$ low spin)

Total = $3 + 2 + 5 + 4 + 1 = 15$.

Thus, the total number of unpaired electrons is 15.

Was this answer helpful?

Similar Questions

  1. A chromium complex with a formula $\text{CrCl}_3\cdot 6\text{H}_2\text{O}$ has a spin only magnetic moment value of $3.87 \text{ BM}$ and its solution conductivity corresponds to $1 : 2$ electrolyte. $2.75 \text{ g}$ of the complex solution was initially passed through a cation exchanger. The solution obtained after the process was reacted with excess of $\text{AgNO}_3$. The amount of $\text{AgCl}$ formed in the above process is _____ g. (Nearest integer)
    [Given: Molar mass in $\text{g mol}^{-1}$ $\text{Cr} : 52; \text{Cl}: 35.5, \text{Ag}: 108, \text{O}: 16, \text{H}: 1$]
  2. Consider the following reactions :
    $\text{NaCl} + \text{K}_2\text{Cr}_2\text{O}_7 + \text{H}_2\text{SO}_4 \rightarrow \text{A} + \text{KHSO}_4 + \text{NaHSO}_4 + \text{H}_2\text{O}$
    $\text{A} + \text{NaOH} \rightarrow \text{B} + \text{NaCl} + \text{H}_2\text{O}$
    $\text{B} + \text{H}_2\text{SO}_4 + \text{H}_2\text{O}_2 \rightarrow \text{C} + \text{Na}_2\text{SO}_4 + \text{H}_2\text{O}$
    In the product 'C', 'X' is the number of $\text{O}_2^{2-}$ units, 'Y' is the total number oxygen atoms present and 'Z' is the oxidation state of Cr. The value of X + Y + Z is ____________.
  3. Identify the metal ions among $\text{Co}^{2+}, \text{Ni}^{2+}, \text{Fe}^{2+}, \text{V}^{3+}$ and $\text{Ti}^{2+}$ having a spin-only magnetic moment value more than $3.0\text{ BM}$. The sum of unpaired electrons present in the high spin octahedral complexes formed by those metal ions is __________.
  4. The crystal field splitting energy of $[\text{Co(oxalate)}_3]^{3-}$ complex is '$n$' times that of the $[\text{Cr(oxalate)}_3]^{3-}$ complex. Here '$n$' is ___________. (Assume $\Delta_o >> P$)

  5. A metal complex with a formula $MCl_4.3NH_3$ is involved in $sp^3d^2$ hybridisation. It upon reaction with excess of $AgNO_3$ solution gives 'x' moles of AgCl. Consider 'x' is equal to the number of lone pairs of electron present in central atom of $BrF_5$. Then the number of geometrical isomers exhibited by the complex is ______
  6. Consider the molecules / ions given below
    $XeO_3$, $BF_4^-$, $I_3^-$, $SF_6$, $PCl_5$
    The ratio of number of molecules having $sp^3d$ hybridisation to those having $sp^3$ hybridisation is ________
  7. In the leaching method, bauxite ore is digested with a concentrated solution of NaOH that produces 'X'. When $CO_2$ gas is passed through the aqueous solution of 'X', a hydrated compound 'Y' is precipitated. 'X' and 'Y' respectively are :-
  8. The total number of possible isomers for square- planar $[Pt(Cl)(NO_2)(NO_3)(SCN)]^{2–}$ is :-
  9. In $KO_2$, the nature of oxygen species and the oxidation state of oxygen atom are, respectively
  10. The correct order of spin-only magnetic moments among the following is : 

    (Atomic number : Mn = 25, Co = 27, Ni= 28, Zn = 30)


Important Questions from Inorganic Chemistry

  1. A chromium complex with a formula $\text{CrCl}_3\cdot 6\text{H}_2\text{O}$ has a spin only magnetic moment value of $3.87 \text{ BM}$ and its solution conductivity corresponds to $1 : 2$ electrolyte. $2.75 \text{ g}$ of the complex solution was initially passed through a cation exchanger. The solution obtained after the process was reacted with excess of $\text{AgNO}_3$. The amount of $\text{AgCl}$ formed in the above process is _____ g. (Nearest integer)
    [Given: Molar mass in $\text{g mol}^{-1}$ $\text{Cr} : 52; \text{Cl}: 35.5, \text{Ag}: 108, \text{O}: 16, \text{H}: 1$]
  2. Consider the following reactions :
    $\text{NaCl} + \text{K}_2\text{Cr}_2\text{O}_7 + \text{H}_2\text{SO}_4 \rightarrow \text{A} + \text{KHSO}_4 + \text{NaHSO}_4 + \text{H}_2\text{O}$
    $\text{A} + \text{NaOH} \rightarrow \text{B} + \text{NaCl} + \text{H}_2\text{O}$
    $\text{B} + \text{H}_2\text{SO}_4 + \text{H}_2\text{O}_2 \rightarrow \text{C} + \text{Na}_2\text{SO}_4 + \text{H}_2\text{O}$
    In the product 'C', 'X' is the number of $\text{O}_2^{2-}$ units, 'Y' is the total number oxygen atoms present and 'Z' is the oxidation state of Cr. The value of X + Y + Z is ____________.
  3. Identify the metal ions among $\text{Co}^{2+}, \text{Ni}^{2+}, \text{Fe}^{2+}, \text{V}^{3+}$ and $\text{Ti}^{2+}$ having a spin-only magnetic moment value more than $3.0\text{ BM}$. The sum of unpaired electrons present in the high spin octahedral complexes formed by those metal ions is __________.
  4. The crystal field splitting energy of $[\text{Co(oxalate)}_3]^{3-}$ complex is '$n$' times that of the $[\text{Cr(oxalate)}_3]^{3-}$ complex. Here '$n$' is ___________. (Assume $\Delta_o >> P$)

  5. Which of the following is the structure of pyrosulphuric acid?
Need Expert Advice?
More Questions from JEE Main

Start Your Preparation with Prepp Mobile App

Download the app from Google Play & App Store
Download the app from Google Play & App Store
Prepp Mobile App