Formulación inorgánica. ÓXIDOS metálicos, no metálicos y haluros de oxígeno (sistemática y stock)

Introduction to Oxides and Their Nomenclature

Overview of Oxides

• The session introduces oxides, which are compounds involving oxygen, emphasizing that oxygen has a valence (oxidation number) of -2.

• It is noted that the position of elements in a compound indicates their electronegativity; the more electronegative element is placed on the right side.

Types of Oxides

• Three types of oxides are identified:

• Metallic Oxides: Composed of oxygen and a metal (e.g., iron).

• Non-metallic Oxides: Composed of oxygen and a non-metal (e.g., nitrogen).

• Oxygen Salts: Involves an element from group 17 combined with oxygen.

Nomenclature Systems for Naming Compounds

Nomenclature Types

• There are three nomenclature systems for naming compounds:

• Systematic Nomenclature

• Stock Nomenclature

• Traditional Nomenclature (not used since 2005 as per IUPAC guidelines).

Systematic Nomenclature

• Systematic nomenclature uses prefixes to indicate the number of atoms:

• Mono-, di-, tri-, tetra-, penta-, etc.

• Example provided: "trióxido de nitrógeno" illustrates how to write systematic names by reversing positions based on oxidation states.

Applying Stock Nomenclature

Understanding Valences

• The example "dióxido de carbono" shows how carbon can have multiple valences (2 or 4), leading to different oxide forms.

• When an element has more than one valence, it requires specifying prefixes like "mono-" for clarity in naming.

Cross Multiplication Method

• In stock nomenclature, oxidation numbers are indicated using parentheses. For instance, iron's oxidation state is shown when naming "óxido de hierro."

Chemical Compounds and Valences

Understanding Manganese Oxide

• The discussion begins with the formation of manganese oxide, emphasizing the correct positioning of oxygen and manganese in the compound.

• A critical point is made about valences; oxygen has a fixed valence while manganese can have multiple valences, necessitating clarity on which one to use.

• The speaker explains how to interchange numbers representing valences between elements to derive the correct formula for manganese oxide.

• Simplification of ratios is discussed, where dividing by two leads to a more straightforward representation of the compound's formula.

• The systematic naming process for compounds is introduced, highlighting how to read from right to left when naming.

Stock System for Naming Compounds

• The importance of knowing manganese's valence is reiterated; without it, proper compound formulation cannot be achieved.

• When discussing copper oxide, it's noted that prefixes like "mono" are necessary if copper has multiple valences; this avoids ambiguity in naming.

• The speaker emphasizes that omitting prefixes when they are needed results in incorrect nomenclature due to potential confusion over different compounds.

Carbon Oxide and Valency Considerations

• Transitioning to carbon oxide, the speaker discusses determining carbon's valence based on its interaction with oxygen’s known valence.

• A correction is made regarding carbon’s assumed valence; it must align with oxygen’s actual behavior rather than an oversimplified view.

Final Thoughts on Oxygen Salts