Tag: werner's theory of coordination compounds

Questions Related to werner's theory of coordination compounds

Which of the following statement(s) is/are correct?

chemistry coordination chemistry werner's theory werner's theory of coordination compounds coordination compounds

  1. Primary valency of the central metal of a complex is always satisfied by anions.

  2. Secondary valency of the central metal of a complex may be satisfied by either negative ions or neutral molecules.

  3. Species which show primary valencies in a complex compound can be precipitated out.

  4. None of the above

Show answer
Correct Option: A,B,C
Explanation:

In short the Werner's theory may be stated as follows:

  1. The central metal in a complex possesses two types of valencies, primary or ionizable valency and secondary valency or non-ionizable valency.
  2. While the primary valency of the metal is variable, the secondary valency has a fixed value. The primary valency refers to the oxidation state and the secondary valency to the coordination number of the metal.
  3. The primary valency is satisfied by only negative ions whereas the secondary valency either by anions or neutral molecules or both.
  4. The secondary valencies are directed in space towards fixed positions around the neutral atom.
Hence, options A, B and C are correct.

When $AgNO _3$ is added to a solution of $Co(NH _3) _5 Cl _3$, the precipitate of $AgCl$ shows two ionized chloride ions. This means:

chemistry coordination chemistry werner's theory werner's theory of coordination compounds coordination compounds

  1. only two chlorine atoms satisfy primary valency and one secondary valency

  2. one chlorine atom satisfies primary as well as secondary valency

  3. two chlorine atoms satisfy primary valency

  4. three chlorine atoms satisfy secondary valency

Show answer
Correct Option: B,C
Explanation:

Option (B),(C) are correct.
When $AgNO _3$ is added to a solution of $Co(NH _3) _5 Cl _3$, the precipitate of $AgCl$ shows two ionized chloride ions.This means one chlorine atom satisfies primary as well as secondary valency and two chlorine atoms satisfy primary valency. Hence, $Co(NH _3) _5 Cl _3$, can be written as $[Co(NH _3) _5 Cl]Cl _2$,