Problem 128 - Chemistry The Science in Context

Question

3\. Many nonmetal oxides react with water to form acidic solutions. Give the formula and name for the acids produced from the following reactions: a. \(P_{4} O_{10}+6 H_{2} O \rightarrow\) b. \(\mathrm{SeO}_{2}+\mathrm{H}_{2} \mathrm{O} \rightarrow\) c. \(\mathrm{B}_{2} \mathrm{O}_{3}+3 \mathrm{H}_{2} \mathrm{O} \rightarrow\)

Step-by-Step Solution

Answer

Question: What are the formulas and names of the acids produced in the following reactions with water: a. \(P_4O_{10} + 6H_2O \rightarrow\) b. \(SeO_2 + H_2O \rightarrow\) c. \(B_2O_3 + 3H_2O \rightarrow\) Answer: a. The acid produced in the reaction \(P_4O_{10} + 6H_2O \rightarrow\) is \(H_3PO_4\) (Phosphoric acid). b. The acid produced in the reaction \(SeO_2 + H_2O \rightarrow\) is \(H_2SeO_3\) (Selenous acid). c. The acid produced in the reaction \(B_2O_3 + 3H_2O \rightarrow\) is \(H_3BO_3\) (Boric acid).

Step 1: a. \(P_4O_{10} + 6H_2O \rightarrow\)

The reaction of nonmetal oxide \(P_4O_{10}\) (Phosphorus pentoxide) with water forms an acid. In this case, \(P_4O_{10}\) reacts with \(6H_2O\) to form an acid. The chemical equation for this reaction is: \(P_{4} O_{10}+6 H_{2} O \rightarrow 4H_{3} PO_{4}\) The formula for the acid produced is \(H_3PO_4\) (Phosphoric acid).

Step 2: b. \(SeO_2 + H_2O \rightarrow\)

The reaction of nonmetal oxide \(\mathrm{SeO}_{2}\) (Selenium dioxide) with water forms an acid. Here, \(\mathrm{SeO}_{2}\) reacts with \( H_2O\) to form an acid. The chemical equation for this reaction is: \(\mathrm{SeO}_{2}+\mathrm{H}_{2} \mathrm{O} \rightarrow H_{2} SeO_{3}\) The formula for the acid produced is \(H_2SeO_3\) (Selenous acid).

Step 3: c. \(B_2O_3 + 3H_2O \rightarrow\)

The reaction of nonmetal oxide \(\mathrm{B}_{2} \mathrm{O}_{departureday3}\) (Boric oxide) with water forms an acid. In this case, \(\mathrm{B}_{2} \mathrm{O}_{3}\) reacts with \(3H_2O\) to form an acid. The chemical equation for this reaction is: \(\mathrm{B}_{2} \mathrm{O}_{3}+3 \mathrm{H}_{2} \mathrm{O} \rightarrow 2H_{3} \mathrm{BO}_{3}\) The formula for the acid produced is \(H_3BO_3\) (Boric acid).

Key Concepts

Nonmetal Oxides

Nonmetal oxides are compounds composed of oxygen and a nonmetal element. These oxides play a significant role in chemistry, especially in the formation of acids. When nonmetal oxides dissolve in water, they often produce acidic solutions. This is because the oxide molecules react with water molecules to form an acid. A key thing to remember is that not all nonmetal oxides exhibit this behavior, but many do. Here are a few points to understand about nonmetal oxides:

• They are usually gases or liquids at room temperature.
• Common examples include sulfur dioxide (SO₂), carbon dioxide (CO₂), and phosphorus pentoxide (P₄O₁₀).
• Nonmetal oxides tend to form acids because the oxygen atoms pull electron density away from the nonmetal atoms, making them more electronegative.

Understanding the properties of nonmetal oxides can help predict which acids will form when they react with water.

Acid Formation

The formation of acids from nonmetal oxides and water is a fascinating chemical process. When a nonmetal oxide reacts with water, it typically undergoes a chemical transformation to form an acidic product. This is a classic example of an acid-base reaction where water acts as the base. Let's explore how this happens:

The nonmetal oxide molecule is generally electron-deficient. When it encounters water molecules, it attracts the lone pairs of electrons present in water. This interaction leads to the formation of a new bond and consequently, an acid. For instance:

• In the case of phosphorus pentoxide ( P₄O₁₀), it reacts with water to form phosphoric acid (H₃PO₄).
• Selenium dioxide (SeO₂) combining with water leads to selenous acid (H₂SeO₃).
• Boric oxide (B₂O₃) reacts with water to produce boric acid (H₃BO₃).

This process illustrates how nonmetal oxides can transform into acids by simply coming in contact with water.

Chemical Equations

Chemical equations are symbolic representations of chemical reactions. They depict the transformation of reactants into products and show the conservation of mass through balanced stoichiometry. When considering the reactions between nonmetal oxides and water, chemical equations become very useful tools for understanding what happens during the reaction.

Each chemical equation has a few standard components:

• Reactants: The starting substances; in our case, nonmetal oxides and water.
• Products: The substances formed; typically acids in these reactions.
• Coefficients: Numbers placed before chemical formulas to ensure atoms are balanced on both sides.

For example, the chemical equation for the reaction of phosphorus pentoxide with water is written as:
\[ P_{4} O_{10} + 6 H_{2} O \rightarrow 4H_{3} PO_{4} \]
This indicates that it takes six molecules of water to fully react with one molecule of phosphorus pentoxide to form four molecules of phosphoric acid. Mastering chemical equations helps to comprehend and predict the results of chemical reactions.