Q. Given the molecular formula of the hexa coordinated complexes $(A)\ CoCl_{3} \bullet 6NH_{3}$ $(B)CoCl_{3} \bullet 5NH_{3}$ $(C)\ CoCl_{3} \bullet 4NH_{3}.$ If the number of coordinated $NH_{3}$ molecules in $A,\ B$ and $C$ respectively are 6, 5 and 4, primary valency in $(A)$, $(B)$ and $(C)\$are
A) 0, 1, 2
B) 3, 2, 1
C) 6, 5, 4
D) 3, 3, 3
Explanation
(b)
The complexes can be written as follows
$\lbrack Co\left( NH_{3} \right)_{6}\rbrack Cl_{3},\lbrack Co\left( NH_{3} \right)_{5}Cl\rbrack Cl_{2},\left\lbrack Co\left( NH_{3} \right)_{4}Cl_{4} \right\rbrack Cl$
Hence, no. of primary valencies are 3, 2 and 1 respectively
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.