Complete the exercises below. Write the formula for each of the following compounds, being sure to use brackets to indicate the coordination sphere: e.g., tris(ethylenediamine)rhodium(III), tris(oxalato)cobaltate(III).

Coordination compounds consist of a central metal atom or ion bonded to surrounding molecules or ions, known as ligands. The arrangement of these ligands around the metal center forms a coordination sphere, which is crucial for determining the compound's properties and reactivity. Understanding the nature of the ligands and their bonding is essential for writing correct formulas.

Ligands are ions or molecules that can donate a pair of electrons to a metal center in a coordination compound. They can be classified as monodentate (binding through one atom) or polydentate (binding through multiple atoms). The type and number of ligands influence the geometry and stability of the coordination complex, which is important when writing the compound's formula.

The nomenclature of coordination compounds follows specific rules set by the International Union of Pure and Applied Chemistry (IUPAC). This includes naming the ligands first, followed by the metal center, and indicating the oxidation state of the metal in Roman numerals. Brackets are used to denote the coordination sphere, which helps clarify the structure of the compound in its formula.