   Chapter 22, Problem 26PS

Chapter
Section
Textbook Problem

Give the formula of a complex constructed from one Cr3+ ion, two ethylenediamine ligands, and two ammonia molecules. Is the complex neutral or is it charged? If charged, give the charge.

Interpretation Introduction

Interpretation: The formula and charge of the complex has to be determined.

Concept introduction:

Coordination compounds: The compounds having coordination covalent bonds which form when metal ions react with polar molecules or anions.

Ligands: The ions or molecules that forms coordination covalent bond with metal ions in a coordination compound. Ligands should have minimum one lone pair of electron, where it donates two electrons to the metal. Metal atom accepts the electron pair from a ligand forming a coordination bond.

Oxidation number: The total number of electrons in an atom after losing or gaining electrons to make a bond with another atom. It indicates the charge of an ion.

The rule to name a coordination complex is,

1. 1. The cation is named before the anion.
2. 2. Within a complex ion, the Ligands are arranged in an alphabetical order followed by the metal ion name. The anionic Ligand should ends with a letter –o, the neutral Ligand are called by the molecules (some common name for some exception).
3. 3. When more Ligands are present, Greek prefixes like di, tri, tetra, penta, and hexa to specify their number.
4. 4. The oxidation number of the metal is represented in roman numerals immediately following the metal ion name.
5. 5. If the complex ion is an anion, the metal name should end with –ate.

Spectrochemical series: The list of ligands arranged in an ascending order of (Δ)(the splitting of d-orbitals in presence of various ligands).

I-<Br-<SCN-<Cl-<S2-<F-<OH-<O2-<H2O<NCS-<edta4-<NH3<  en<NO2-<CN-<COweak-fieldincreasing(Δ)strong-fieldligandsligands

Explanation

The complex contains one ethylenediamine and two ammonia molecules as ligands and Cr3+ is the central metal ion.

The ligands can be written as,

ammoniaNH3ethylenediamineen

The formula of the complex is [Cr(en)2(NH3)2]

The oxidation state is,

Oxidation number ofNH3=0Oxidation number ofen=0Oxidation

Still sussing out bartleby?

Check out a sample textbook solution.

See a sample solution

The Solution to Your Study Problems

Bartleby provides explanations to thousands of textbook problems written by our experts, many with advanced degrees!

Get Started

Find more solutions based on key concepts 