[Química] Nomenclatura 💡 PERÓXIDOS

Summary

In this video, the focus is on the nomenclature of peroxides, a unique group of unstable compounds. The explanation covers three main naming conventions: common, stock, and IUPAC. Peroxides, which differ from regular oxides by having oxygen atoms in a -1 oxidation state, are named by combining the metal’s root with appropriate suffixes based on oxidation states. The script walks through various examples, including peroxides of lithium, calcium, iron, sodium, nickel, and hydrogen, highlighting the differences in naming conventions and helping viewers understand how to properly identify and name peroxides in chemical formulas.

Takeaways

• 😀 Peroxides are a family of compounds where oxygen has an oxidation state of -1, unlike the usual -2 state.
• 😀 The unique bonding in peroxides creates a bond known as the 'John peroxide' structure, where two oxygen atoms are bonded with oxidation states of -1 each.
• 😀 Nomenclature for peroxides follows similar rules to oxides but differs in the family name, which is always 'peroxide'.
• 😀 In common nomenclature, metals are named with the suffix '-oso' or '-ico', depending on their oxidation state, just like in metallic oxides.
• 😀 In systematic (stock) nomenclature, metals are named with their oxidation state in Roman numerals, e.g., 'peroxide of lithium'.
• 😀 The IUPAC nomenclature uses prefixes to indicate the number of atoms of each element (e.g., 'di' for two oxygen atoms), simplifying the process.
• 😀 Peroxide formulas should not be simplified to maintain the 'peroxide' identity (e.g., Na2O2 for sodium peroxide).
• 😀 For peroxides like lithium peroxide (Li2O2), the oxidation state of lithium is +1, balancing the negative charges from oxygen.
• 😀 The naming of complex peroxides requires attention to oxidation states; for example, iron peroxide (Fe2O3) can be named based on the highest oxidation state of iron.
• 😀 The common name for hydrogen peroxide (H2O2) is 'hydrogen peroxide' or 'water oxygenated', but in formal nomenclature, it is 'peroxide of hydrogen'.

Q & A

What is the general oxidation state of oxygen in peroxides?

In peroxides, oxygen has an oxidation state of -1, which is different from its usual oxidation state of -2 in other compounds.

Why are peroxides considered an exception to the usual behavior of oxygen?

Peroxides are an exception because oxygen normally has an oxidation state of -2, but in peroxides, each oxygen atom has an oxidation state of -1.

What is the significance of the 'Johann peróxido' bond mentioned in the video?

The 'Johann peróxido' bond refers to the connection between two oxygen atoms in peroxides, where both have an oxidation state of -1, forming a peroxide group (O2).

What is the main difficulty in identifying peroxides based on their formulas?

The main difficulty in identifying peroxides is that they resemble oxides, as both involve oxygen, but peroxides have a distinct bonding structure where oxygen atoms are connected and have an oxidation state of -1.

How do you determine the oxidation state of a metal in a peroxide compound?

To determine the oxidation state of a metal in a peroxide, balance the total charge of the peroxide group (which is -2) with the oxidation state of the metal so that the compound is electrically neutral.

How is the common nomenclature for peroxides similar to that of metal oxides?

The common nomenclature for peroxides follows the same structure as for metal oxides, where the metal is named with the suffix -oso or -ico based on its oxidation state.

What is the key difference between the common and stock nomenclature systems for peroxides?

The key difference is that the stock nomenclature includes Roman numerals to indicate the oxidation state of metals with multiple oxidation states, while the common nomenclature uses traditional naming based on oxidation states like -oso or -ico.

What is the role of Roman numerals in stock nomenclature for peroxides?

In stock nomenclature, Roman numerals are used to indicate the oxidation state of metals that have more than one possible oxidation state. For example, 'ferric' indicates iron in the +3 oxidation state.

Why is the IUPAC nomenclature for peroxides considered simpler?

The IUPAC nomenclature is simpler because it uses prefixes to indicate the number of atoms in the compound, rather than requiring knowledge of oxidation states.

What is the common name for hydrogen peroxide, and how does it relate to its formal nomenclature?

The common name for hydrogen peroxide is 'agua oxigenada' in Spanish. Its formal nomenclature is 'peróxido de hidrógeno' in the common system and 'dióxido de hidrógeno' in IUPAC nomenclature.