default_background
✕

Find the best tutors and institutes for Class 12 Tuition

Find Best Class 12 Tuition

Please select a Category.

Please select a Locality.

No matching category found.

No matching Locality found.

Q5.23 (iii):
Give the oxidation state, d orbital occupation and coordination number of the central metal ion: ((NH_{4})_{2}[CoF_{4}])

Solution :

Step 1: Identification of the Complex Species

The given coordination entity is $(NH_{4})_{2}[CoF_{4}]$. The coordination sphere is $[CoF_{4}]^{2-}$. To determine the oxidation state of the central metal ion (Cobalt), we must analyze the total charge of the complex.

Dissociation: $(NH_{4})_{2}[CoF_{4}] \rightarrow 2NH_{4}^{+} + [CoF_{4}]^{2-}$

Step 2: Calculation of the Oxidation State of Cobalt ($Co$)

Let $x$ be the oxidation state of $Co$. The fluoride ion ($F^{-}$) carries a charge of $-1$. [Per the rules of oxidation state calculation in coordination complexes]:

$x + 4(-1) = -2$

$x - 4 = -2$

$x = +2$

The oxidation state of the central metal ion $Co$ is $+2$.

Step 3: Determining the $d$-orbital Occupation

The atomic number of Cobalt ($Co$) is $27$. The ground state electronic configuration is $[Ar] 3d^{7} 4s^{2}$.

For $Co^{2+}$ (removing two electrons from the $4s$ orbital):

Configuration of $Co^{2+} = [Ar] 3d^{7}$

Since $F^{-}$ is a weak field ligand [Per Spectrochemical Series], it does not cause pairing of electrons in the $d$-orbitals. The distribution follows Hund's rule of maximum multiplicity:

$t_{2g}$ orbitals contain 5 electrons ($t_{2g}^5$) and $e_g$ orbitals contain 2 electrons ($e_g^2$) in an octahedral environment, but for this tetrahedral complex, the notation is $e^4 t_2^3$.

d-orbital occupation: $t_{2g}^5 e_g^2$ (for octahedral) or $e^4 t_2^3$ (for tetrahedral).

Step 4: Coordination Number (C.N.)

The coordination number is determined by the number of donor atoms directly bonded to the central metal ion. Here, four $F^{-}$ ions are monodentate ligands attached to the central $Co^{2+}$ ion.

$\text{C.N.} = 4 \times (\text{denticity of } F^{-}) = 4 \times 1 = 4$

Tetrahedral Geometry [CoF4]²⁻ Co²⁺ F⁻ F⁻ F⁻

Summary Table

Parameter Value
Oxidation State $+2$
d-orbital Occupation $d^{7}$ ($e^4 t_2^3$)
Coordination Number $4$

Final Solution: The central metal ion $Co$ has an oxidation state of $+2$, a $d$-orbital occupation of $d^{7}$, and a coordination number of $4$.


More Questions from Class 12 Chemistry Coordination Compounds Exercises


CBSE Solutions for Class 12 Chemistry Coordination Compounds


Chapters in CBSE - Class 12 Chemistry


Top Tutors who teach Coordination Compounds

(27)
Top Tutor
locationImg Gaur City 2, Noida
experience 8 yrs of Exp students 10 students
greenClock 388 hrs of classes completed
rsIcon 100 per hour
"Experienced & certified Maths tutor with 8 years of experience in teaching mathematics"
Online Classes Online Classes

Maths tutor with 8 years of experience in teaching maths at SGB Coaching Institute Mau Uttar Pradesh.

Adhya Singh

Your teaching has truly made a difference in my understanding—thank you for being such a dedicated and inspiring teacher!

Skills: Mathematics , Applied Mathematics
Also teaches: Class 10 Tuition, Class 11 Tuition and more

(11)
superTutorSuper Tutor
locationImg NH21 Sundernagar, Sundernagar
experience 5 yrs of Exp students 4 students
greenClock 186 hrs of classes completed
rsIcon 500 per hour
Physics professional teacher of teaching experience of 5 years
Online Classes Online Classes

My experience of teaching is great. I teach with great enthusiasm and we will make this teaching learning process easy and interesting together.

Suhani Singh

Way of teaching simply I liked. I understood everything. I have started understanding numerical too.

Skills: Physics
Also teaches: Class 11 Tuition, Class 10 Tuition and more

(2)
Top Tutor
locationImg Pudur, Coimbatore
experience 6 yrs of Exp students 1 student
greenClock 62 hrs of classes completed
rsIcon 1000 per hour
Online Classes Online Classes
homeTutions Student's Home
regularClasses Tutor's home

I have completed MPhil in Physics and teaching in college for 6 years. I am giving online/ home tuition since 2015. I prefer mathematics .

Skills: English , Mathematics and more
Also teaches: Class 11 Tuition, Class 10 Tuition and more

(15)
Top Tutor
locationImg Malviya Nagar, Delhi
experience 20 yrs of Exp students 4 students
greenClock 255 hrs of classes completed
rsIcon 600 per hour
International Educator (English & French), Certified Expert-Teacher (from Planet Spark & Turito)
Online Classes Online Classes

I feel myself God-blessed, having been able to guide thousands of students/learners English, as a school subject as well as a language since 1992. I'm glad to notice that these learners have not only been doing well in their respective areas but also excelling in the real-life situations. May God bless them!!

Nishtha Goel jain

My one-on-one tutoring experience in English and French was exceptional. The lessons were customized to my learning style and pace, which made a huge difference. My tutor was patient and skilled, offering clear explanations that helped me better understand grammar and improve my speaking abilities in both languages. The sessions were engaging, with interactive exercises and valuable feedback that kept me motivated. I've gained confidence in using English and French daily, and I highly recommend this personalized tutoring service!

Skills: English , French

(5)
Top Tutor
locationImg Kalindi Vihar, Agra
experience 5 yrs of Exp
rsIcon 350 per hour
Learning is an Eternal Realm of Exploring
Online Classes Online Classes
regularClasses Tutor's home

I am working as an Assistant Professor in the Department of Civil and Engineering at Hindustan College of Science and Technology, Mathura. I completed my post-graduation with Honours in Geotechnical and Geo-environmental engineering from Kamla Nehru Institute of Technology (KNIT), Sultanpur in 2016. Since then i engaged in teaching and Research work, I taught many civil engineering Subjects basically, Geotechnical Engineering, Foundation Design, Strength of Material, Structure, Fluid Mechanics, Survey, Hydraulic and Hydraulics Machines. Having 5 years of experience gives me major exposure for being a professional tutor and mentor for the development of students.

Skills: Mathematics , Physics
Also teaches: MTech Tuition, Spiritual Workshop and more

Other Subjects in CBSE - Class 12

Worksheet Icon

Download free CBSE - Class 12 Chemistry Coordination Compounds Exercises worksheets

Download Now

Find Best Class 12 Tuition ?

Find Now »