Problem 8 - Chemistry: Principles and Reactions

Question

Write the formula of the acid formed when each of these acidic oxides reacts with water. (a) \(\mathrm{SO}_{2}\) (b) \(\mathrm{Cl}_{2} \mathrm{O}\) (c) \(\mathrm{P}_{4} \mathrm{O}_{6}\)

Step-by-Step Solution

Answer

Answer: The acids formed are: (a) H₂SO₃ (sulfurous acid), (b) HOCl (hypochlorous acid), and (c) H₃PO₃ (phosphorous acid).

Step 1: (a) SO₂ acidic oxide

Since sulfur has a valence of +4 in SO₂ and oxygen has a valence of -2 in oxides, we will use these valencies to form a balanced chemical equation when SO₂ reacts with water. The balanced chemical equation for the reaction with water is: SO₂ + H₂O → H₂SO₃ Hence, the formula of the acid formed when SO₂ reacts with water is H₂SO₃ (sulfurous acid).

Step 2: (b) Cl₂O acidic oxide

In Cl₂O, chlorine has a valence of +1 and oxygen has a valence of -2 in oxides. Using these valencies, we can form a balanced chemical equation for the reaction with water. The balanced chemical equation for the reaction with water is: 2 Cl₂O + 2 H₂O → 4 HOCl Hence, the formula of the acid formed when Cl₂O reacts with water is HOCl (hypochlorous acid).

Step 3: (c) P₄O₆ acidic oxide

For P₄O₆, phosphorus has a valence of +3 and oxygen has a valence of -2 in oxides. We can now form a balanced chemical equation for the reaction with water. The balanced chemical equation for the reaction with water is: P₄O₆ + 6 H₂O → 4 H₃PO₃ Hence, the formula of the acid formed when P₄O₆ reacts with water is H₃PO₃ (phosphorous acid).

Key Concepts

Chemical Reactions

Chemical reactions are fascinating processes where substances known as reactants are transformed into new substances called products.
These reactions involve the breaking and forming of chemical bonds, leading to new arrangements of atoms.

• In a basic sense, a chemical reaction can be thought of as a rearrangement of atoms.
• Oxides, which often serve as reactants, can be metal or non-metal oxides. Acidic oxides specifically are non-metal oxides that react with water to form acids.

This process of converting non-metal oxides into acids happens through chemical reactions involving water. It's a clear example of how the properties of elements can determine the expected chemical transformations.

Acid Formation

Acid formation is a key concept in chemistry, particularly when discussing non-metal oxides reacting with water.
When acidic oxides meet with water, they undergo a chemical reaction to form an acid.

• This is because these non-metal oxides have a high electronegativity, allowing them to attract and bind to oxygen and hydrogen from water.
• Take sulfur dioxide ( SO₂ ), for example, which reacts with water to form sulfurous acid ( H₂SO₃ ). This process illustrates how the combination of elements with water can lead to acid production.

Understanding the formation of different acids aids in grasping more complex chemical processes and emphasizes the role of non-metallic oxides in nature and industry.

Chemical Equations

Chemical equations are essential tools for representing chemical reactions. They tell us about the reactants, products, and the proportions in which they react or form.
Each side of a chemical equation should balance, meaning the number of atoms for each element remains constant.

• For instance, with sulfur dioxide ( SO₂ ), combining with water results in the chemical equation: SO₂ + H₂O → H₂SO₃ . Each atom is accounted for on either side of the equation.
• Similarly, chlorine monoxide ( Cl₂O ) reacts with water forming hypochlorous acid, represented as: 2 Cl₂O + 2 H₂O → 4 HOCl .

Understanding how to balance chemical equations is crucial as it reflects the law of conservation of mass. Thus, chemical equations not only depict chemical reactions but also ensure the precision of atom conservation and transformation.