Question

Which of the following is the most likely structure of CrCl₃.6H₂O if `1/3` of total chlorine of the compound is precipitated by adding AgNO₃ to its aqueous solution?

Options

• [Cr(H₂O)₆]Cl₃

• [Cr(H₂O)₄Cl₂]Cl.2H₂O

• [Cr(H₂O)₅Cl]Cl₂.H₂O

• [Cr(H₂O)₃Cl₃](H₂O)₃

Answer 1

[Cr(H₂O)₄Cl₂]Cl.2H₂O

Explanation:

In the given molecule, there is 3 Cl present, and `(1/3) xx 3` = 1 Cl is precipitated per molecule.

So, 1 Cl satisfies the primary valence and is ionizable.

So 1 Cl will be present outside the coordination sphere.

So the correct structure is [Cr(H₂O)₄Cl₂]Cl.2H₂O.