Question

Rank the following oxides in order of increasing acidity in water: \(\mathrm{Sb}_{2} \mathrm{O}_{3}, \mathrm{Bi}_{2} \mathrm{O}_{3}, \mathrm{P}_{4} \mathrm{O}_{10} \cdot \mathrm{Sb}_{2} \mathrm{O}_{5}\)

Short answer

\[\mathrm{Bi}_{2} \mathrm{O}_{3}\] < \[\mathrm{Sb}_{2} \mathrm{O}_{3}\] < \[\mathrm{Sb}_{2} \mathrm{O}_{5}\] < \[\mathrm{P}_{4} \mathrm{O}_{10}\]

Step-by-step solution

- Identify the Nature of the Oxides

Determine whether the given oxides are basic, amphoteric, or acidic. Generally, metal oxides are basic, non-metal oxides are acidic, and oxides of metalloids can be amphoteric.

- Analyze the Oxides

Examine each oxide:- \[\mathrm{Sb}_{2} \mathrm{O}_{3}\] (Antimony(III) oxide) is an amphoteric oxide.- \[\mathrm{Bi}_{2} \mathrm{O}_{3}\] (Bismuth(III) oxide) is a weakly basic oxide.- \[\mathrm{P}_{4} \mathrm{O}_{10}\] (Phosphorus pentoxide) is a strongly acidic oxide.- \[\mathrm{Sb}_{2} \mathrm{O}_{5}\] (Antimony(V) oxide) is more acidic compared to \[\mathrm{Sb}_{2} \mathrm{O}_{3}\].

- Rank the Oxides by Acidity

Based on their nature:1. \[\mathrm{Bi}_{2} \mathrm{O}_{3}\] (weakly basic)2. \[\mathrm{Sb}_{2} \mathrm{O}_{3}\] (amphoteric)3. \[\mathrm{Sb}_{2} \mathrm{O}_{5}\] (more acidic than \[\mathrm{Sb}_{2} \mathrm{O}_{3}\])4. \[\mathrm{P}_{4} \mathrm{O}_{10}\] (strongly acidic)

Key concepts

Acidic Oxides

Acidic oxides are substances that react with water to form acids. They are typically composed of non-metals. For example, \(\text{P}_4\text{O}_{10}\) (phosphorus pentoxide) reacts with water to produce phosphoric acid (\(\text{H}_3\text{PO}_4\)). Acidic oxides can also react with bases to form salts and water.

Some common characteristics of acidic oxides include:

• They are usually non-metal oxides.
• They have a higher oxidation state for the non-metal atom.
• They form acids when dissolved in water.

In the given exercise, \(\text{P}_4\text{O}_{10}\) is an example of a strongly acidic oxide.

Amphoteric Oxides

Amphoteric oxides have the unique ability to react with both acids and bases. This makes them neither completely basic nor completely acidic. An example from the exercise is \(\text{Sb}_2\text{O}_3\) (antimony(III) oxide).

Characteristics of amphoteric oxides include:

• They can react with both acids and bases to form salts and water.
• They are usually found in elements that are metalloids or have intermediate properties.
• They may show different behavior depending on the reactants.

In the ranking task, \(\text{Sb}_2\text{O}_3\) has an intermediate position due to its amphoteric nature.

Basic Oxides

Basic oxides are those that react with water to form bases, or with acids to produce salts and water. They are typically formed from metal elements. In the exercise, \(\text{Bi}_2\text{O}_3\) (bismuth(III) oxide) is identified as a weakly basic oxide.

Key traits of basic oxides include:

• They are usually metal oxides.
• They have lower oxidation states for the metal atom.
• They produce basic solutions (alkalies) when they dissolve in water.

Because \(\text{Bi}_2\text{O}_3\) is weakly basic, it ranks lowest in acidity in the provided exercise.

Chemistry Education

Understanding the acidity of oxides is fundamental in chemistry education. It helps students learn about the properties and behaviors of different compounds. It also aids in predicting reactions and understanding the periodic table.

Here are some educational tips:

• Use visual aids like diagrams to show how oxides react with water.
• Practice with real-life examples and applications, such as pollution control and material science.
• Encourage hands-on experiments where safe to help students grasp concepts better.

By studying oxides, students can better understand fundamental chemical principles and see their applications in the real world.