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Grade 6Physical Chemistry

calculate the spin only magnetic and total angula

calculate the spin only magnetic and total angular moment for
1-Na2(Ni CL4)
2-CL2(Cr(H2O))
3-K4(CO(CN)4)
Profile image of SOHAIR SABRY
9 Years agoGrade 6
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1 Answer

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Askiitians Tutor Team

ApprovedApproved Tutor Answer1 Year ago

To calculate the spin-only magnetic moment and total angular momentum for the given coordination complexes, we need to consider the electronic configurations of the metal ions involved, their oxidation states, and the geometry of the complexes. Let's break this down for each compound step by step.

1. Na2(NiCl4)

In this complex, nickel (Ni) is in the +2 oxidation state. The electron configuration for Ni is [Ar] 3d8 4s2. When it loses two electrons to form Ni2+, the configuration becomes 3d8.

Determining the Spin State

Nickel(II) typically has a square planar geometry in complexes like NiCl42-. In this arrangement, the 3d orbitals split into two sets: the lower energy (dx2-y2 and dz2) and the higher energy (dxy, dyz, and dzx). For Ni2+, the 3d8 configuration will have two unpaired electrons, leading to a high-spin state.

Calculating the Spin-Only Magnetic Moment

The formula for the spin-only magnetic moment (μs) is:

μs = √(n(n + 2))

where n is the number of unpaired electrons. For Ni2+, n = 2:

μs = √(2(2 + 2)) = √(8) = 2.83 BM (Bohr Magneton)

Total Angular Momentum

The total angular momentum (J) can be calculated using the formula:

J = √[j(j + 1)]

For two unpaired electrons, j = 1 (since j = s + l, where s = 1/2 and l = 0 for d electrons). Thus:

J = √[1(1 + 1)] = √2 = 1.41

2. Cr(H2O)Cl2

In this complex, chromium (Cr) is in the +3 oxidation state. The electron configuration for Cr is [Ar] 3d5 4s1. For Cr3+, the configuration becomes 3d3.

Analyzing the Spin State

Chromium(III) typically adopts an octahedral geometry. In this case, the 3d orbitals will split into two sets (t2g and eg). With three electrons in the 3d orbitals, all three will occupy the lower energy t2g orbitals, resulting in three unpaired electrons.

Spin-Only Magnetic Moment Calculation

Using the same formula:

μs = √(n(n + 2))

For Cr3+, n = 3:

μs = √(3(3 + 2)) = √(15) = 3.87 BM

Finding Total Angular Momentum

For three unpaired electrons, j = 3/2:

J = √[3/2(3/2 + 1)] = √(15/4) = 1.94

3. K4(CO(CN)4)

In this complex, cobalt (Co) is in the +2 oxidation state. The electron configuration for Co is [Ar] 3d7 4s2. For Co2+, the configuration becomes 3d7.

Understanding the Spin State

Cobalt(II) typically forms a tetrahedral complex in this case. In a tetrahedral field, the 3d orbitals split into two sets (e and t2). For Co2+ with 3d7, there will be three unpaired electrons in the higher energy t2 orbitals, resulting in a high-spin state.

Calculating the Spin-Only Magnetic Moment

For Co2+, n = 3:

μs = √(3(3 + 2)) = √(15) = 3.87 BM

Total Angular Momentum Calculation

For three unpaired electrons, j = 3/2:

J = √[3/2(3/2 + 1)] = √(15/4) = 1.94

Summary of Results

  • Na2(NiCl4): μs = 2.83 BM, J = 1.41
  • Cr(H2O)Cl2: μs = 3.87 BM, J = 1.94
  • K4(CO(CN)4): μs = 3.87 BM, J = 1.94

These calculations provide insight into the magnetic properties and angular momentum of the complexes based on their electronic configurations and geometries. Understanding these concepts is crucial for predicting the behavior of transition metal complexes in various chemical environments.


question mark

In the reaction A + 2B ⇌ 2C, if 2 moles of A, 3 moles of B and 2 moles of C are placed in a 2 L flask and
the equilibrium concentration of C is 0.5 mol/L. The equilibrium constant (KC) for the reaction is.....and please tell how you know that the reaction is going forward .. imean how to calculate the reaction quotient ???

physical chemistry

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