Q: Binary transition-metal compounds, such as the oxides and sulfides, are usually written with idealized what?


Read this paragraph and choose the correct option from the provided answers:

VII *The convention of using roman numerals to indicate the oxidation states of a metal is used here. Binary transition-metal compounds, such as the oxides and sulfides, are usually written with idealized stoichiometries, such as FeO or FeS, but these compounds are usually cation deficient and almost never contain a 1:1 cation:anion ratio. Thus a substance such as ferrous oxide is actually a nonstoichiometric compound with a range of compositions. The acid–base character of transition-metal oxides depends strongly on the oxidation state of the metal and its ionic radius. Oxides of metals in lower oxidation states (less than or equal to +3) have significant ionic character and tend to be basic. Conversely, oxides of metals in higher oxidation states are more covalent and tend to be acidic, often dissolving in strong base to form oxoanions.

 Choices:

- speciation

- fluctuations

- noble gases

- stoichiometries


A:
stoichiometries