Question

Which of the following types of valences, according to Werner’s theory, is also called primary valence?

• A. Ionisable valence
• B. Auxiliary valence
• C. Residual valence
• D. Subsidiary valence

Hint:

In Werner’s theory: Primary valence = ionisable valence, Secondary valence = coordination number.

Answer 1

The Correct Option is A

Step 1: Werner’s coordination theory.
According to Werner’s theory, metals exhibit two types of valences: primary and secondary valence. These explain the bonding behavior in coordination compounds.

Step 2: Meaning of primary valence.
Primary valence corresponds to the oxidation state of the metal and is satisfied by ions. It is ionisable in nature.

Step 3: Relation with ionisable valence.
Since primary valence can be ionised in solution, it is also called ionisable valence.

Step 4: Conclusion.
Thus, primary valence is correctly referred to as ionisable valence.