#IT
398 Views

Werner theory and it's postulate


Answer (1)
Tushar Karmakar 30th Apr, 2020

The important postulates of Werner’s theory are:


The central metal or the metal atoms in coordination compounds show two types of valency. They are the primary and secondary valency.

The primary valency relates to the oxidation state and the secondary valency relates to the coordinate number.

The number of secondary valences is fixed for every metal atom. It means that the coordination number is fixed.

The metal atom works towards satisfying both its primary and secondary valencies. A negative ion satisfies the primary valency. On the other hand, a negative ion or neutral molecules satisfy secondary valencies.

The secondary valencies point towards a fixed position in space. This is the reason behind the definite geometry of the coordinate compound. For example, let us consider the case of a metal ion having six secondary valencies. These arrange octahedrally around the central metal ion. If the metal ion has four secondary valencies, these arrange in either tetrahedral or square planar arrangement around the central metal ion. Therefore, we see that the secondary valency determines the stereochemistry of the complex ion. On the other hand, the primary valency is non-directional.

Related Questions

UPES B.Tech Admissions 2026
Apply
Ranked #43 among Engineering colleges in India by NIRF | Highest Package 1.3 CR , 100% Placements
UPES Integrated LLB Admission...
Apply
Ranked #18 amongst Institutions in India by NIRF | Ranked #1 in India for Academic Reputation by QS Rankings | 16 LPA Highest CTC
Presidency University MBA Adm...
Apply
NAAC A+ Accredited | Highest CTC 10 LPA | Top Recruiters : Amazon, Accenture, KPMG, EY, Capgemini & many more
Nirma University Law Admissio...
Apply
Grade 'A+' accredited by NAAC | Ranked 33rd by NIRF 2025
UPES M.Tech Admissions 2026
Apply
Ranked #45 Among Universities in India by NIRF | 1950+ Students Placed 91% Placement, 800+ Recruiters
UPES | BBA Admissions 2026
Apply
#36 in NIRF, NAAC ‘A’ Grade | 100% Placement, up to 30% meritorious scholarships
View All Application Forms

Download the Careers360 App on your Android phone

Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile

150M+ Students
30,000+ Colleges
500+ Exams
1500+ E-books