Problem 3 - General Chemistry: Principles and Modern Applications

Question

The oxides of the phosphorus(III), antimony(III), and bismuth(III) are \(\mathrm{P}_{4} \mathrm{O}_{6}, \mathrm{Sb}_{4} \mathrm{O}_{6},\) and \(\mathrm{Bi}_{2} \mathrm{O}_{3} .\) Only one of these oxides is amphoteric. Which one? Which of these oxides is most acidic? Which is most basic?

Step-by-Step Solution

Answer

Antimony(III) oxide (Sb4O6) is the amphoteric oxide, Phosphorus(III) oxide (P4O6) is the most acidic oxide, and Bismuth(III) oxide (Bi2O3) is the most basic oxide.

Step 1: Identify the Amphoteric Oxide

Amphoteric oxides can react with both acids and bases. Antimony(III) oxide (Sb4O6) meets this characteristic, therefore it is the amphoteric oxide.

Step 2: Identify the Most Acidic Oxide

The acidity of an oxide increases with increasing oxidation state. Phosphorus(III) oxide (P4O6) has the most electrons in an oxidation state, making it the most acidic oxide.

Step 3: Identify the Most Basic Oxide

Basic oxides react with acids to form a salt and water. Out of the given oxides, Bismuth(III) oxide (Bi2O3) has the least number of electrons in an oxidation state. Hence, it tends to donate electrons, which is a characteristic of bases. Therefore, Bi2O3 is the most basic oxide.

Key Concepts

Acidic Oxides

Acidic oxides are chemical compounds that react with water to form an acidic solution or with a base to form a salt. Mainly, they are non-metal oxides. These oxides can be found throughout the periodic table but are more common among the elements to the right of the table.
Phosphorus, sulfur, and carbon are some examples of elements that can form acidic oxides. For instance, phosphorus(III) oxide (\(\mathrm{P}_{4} \mathrm{O}_{6}\)) is known for its acidic properties. It can react with water to form phosphorous acid \(\mathrm{H}_{3} \mathrm{PO}_{3}\).
Characteristics of acidic oxides include:

• They increase in acidity with an increase in the element's oxidation state.
• They generally form acidic solutions when dissolved in water.
• They usually react with bases to produce a salt and water.

Understanding acidic oxides helps in predicting reactions involving non-metals and influences decisions in industrial and environmental chemistry.

Basic Oxides

Basic oxides are typically metallic oxides that interact with acids to yield salt and water. Often, these compounds come from the left side of the periodic table, where elements are metals.
A perfect example of a basic oxide is bismuth(III) oxide (\(\mathrm{Bi}_{2} \mathrm{O}_{3}\)). It reacts with hydrochloric acid \(\mathrm{HCl}\) to form bismuth chloride \(\mathrm{BiCl}_3\) and water.
Here are some features of basic oxides:

• They tend to be ionic in nature due to the metal atoms donating electrons.
• They can form basic solutions when dissolved in water. However, not all basic oxides are sufficiently soluble to show this property clearly.
• They react with acids in neutralization reactions.

Recognizing basic oxides is crucial in understanding base behavior in chemical reactions, particularly in mining and material sciences.

Phosphorus(III) Oxide

Phosphorus(III) oxide, also known as tetraphosphorus hexoxide, is represented by the molecular formula \(\mathrm{P}_{4} \mathrm{O}_{6}\). It forms when elemental phosphorus burns in a limited supply of oxygen.
Notably, this oxide is highly reactive with water, forming phosphorous acid \(\mathrm{H}_{3} \mathrm{PO}_{3}\), showcasing its acidic nature. This reaction also emphasizes the oxide's importance in producing phosphorus compounds in industrial settings.
Key points about phosphorus(III) oxide include:

• Acts as an acidic oxide because it forms an acid when interacting with water.
• Responsive to bases, participating in neutralization reactions to form salts.
• Exhibits a molecular compound structure with covalent characteristics due to the involvement of a non-metal.

Such properties illustrate its role and significance in chemical processing and compound synthesis.

Antimony(III) Oxide

Antimony(III) oxide has the chemical formula \(\mathrm{Sb}_{4} \mathrm{O}_{6}\), known for its amphoteric behavior. This means it can react both with acidic and basic environments.
In acidic solutions, antimony(III) oxide behaves like a base, while in basic solutions, it acts as an acid, making it a versatile compound in laboratory and industrial reactions.
Highlights of antimony(III) oxide include:

• Exhibits amphoteric nature, making it versatile in different chemical environments.
• Used in flame retardant formulations due to its stability and reactivity features.
• Forms antimonite salts during reactions with strong bases.

This adaptability makes antimony(III) oxide a key player in complex syntheses and various industrial applications.

Bismuth(III) Oxide

The compound bismuth(III) oxide, noted as \(\mathrm{Bi}_{2} \mathrm{O}_{3}\), is a prominent basic oxide. It typically does not react much with water but interacts effectively with acids.
When bismuth(III) oxide reacts with acids, it produces salts and water, behaving as a typical base would in neutralization processes.
Essential attributes of bismuth(III) oxide include:

• Primarily behaves as a basic compound due to its tendency to donate electrons in reactions.
• Used in catalysis and material sciences for its thermal stability and electronic properties.
• Forms bismuth-based salts when reacting with acids, making them useful in various applications.

Such versatility and functionality enhance its usage in both synthetic chemistry and technological applications.