Question

When a coordination compound \[CrC{l_3}.6{H_2}O\] is mixed with \[AgN{O_3}\], 2 moles of AgCl are precipitated per mole of the compound. Write
(i) Structural formula
(ii) IUPAC name of the complex

Answer 1

Hint: As only one mole of \[CrC{l_3}.6{H_2}O\]is present so 2 mole of AgCl will be precipitated. The coordination number of the compound formed is 6.

Complete Step by Step Solution:
Coordination compounds are defined as a compound where the central metal atom is surrounded by nonmetal atoms or sometimes groups of atoms known as ligands bonded to each other by a chemical bond.

It is given that a coordination compound \[CrC{l_3}.6{H_2}O\] is mixed with \[AgN{O_3}\], 2 moles of AgCl are precipitated per mole of the compound.
When a coordination compound with chemical formula \[CrC{l_3}.6{H_2}O\] is mixed with \[AgN{O_3}\], 2 moles of AgCl are precipitated out, so the structural formula of the compound formed will contain two chloride ions \[C{l^ - }\]satisfying the primary valencies. Five water molecules (\[{H_2}O\] ) and one chloride ion \[C{l^ - }\] are also present in the coordination sphere which makes the total coordination number 6. One water molecule acts as a molecule of hydration.

Coordination number is defined as the total number of ions, atoms or molecules a central atom in a coordination compound possesses.
The structural formula of the compound is \[[CrCl{({H_2}O)_5}]C{l_2}.{H_2}O\].
The IUPAC name of the complex is pentaaquachlorochromium (III) chloride monohydrate.

Note: It should be noted that the water molecule of hydration is not bonded to the central atom or transition atom and therefore it is not included while calculating the coordination number of the coordination compound.