Problem 38 - Chemistry The Central Science

Question

Classify each of the following aqueous solutions as a nonelectrolyte, weak electrolyte, or strong electrolyte: (a) \(\mathrm{LiClO}_{4}\), (b) \(\mathrm{HClO}\), (c) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{OH}\) (propanol), \((\mathbf{d}) \mathrm{HClO}_{3}\) (e) \(\mathrm{CuSO}_{4}\), \((\mathbf{f}) \mathrm{C}_{12} \mathrm{H}_{22} \mathrm{O}_{11}\) (sucrose).

Step-by-Step Solution

Answer

The classifications of the given aqueous solutions are as follows: a. \(\mathrm{LiClO}_{4}\): Strong electrolyte b. \(\mathrm{HClO}\): Weak electrolyte c. \(\mathrm{CH}_{3}\mathrm{CH}_{2}\mathrm{CH}_{2}\mathrm{OH}\) (propanol): Nonelectrolyte d. \(\mathrm{HClO}_{3}\): Strong electrolyte e. \(\mathrm{CuSO}_{4}\): Strong electrolyte f. \(\mathrm{C}_{12}\mathrm{H}_{22}\mathrm{O}_{11}\) (sucrose): Nonelectrolyte

Step 1: Identify compound types for each solution

First, let us identify the compound types/formulas for each solution: a. \(\mathrm{LiClO}_4\) (lithium perchlorate) - Ionic salt b. \(\mathrm{HClO}\) (hypochlorous acid) - Weak acid c. \(\mathrm{CH}_{3}\mathrm{CH}_{2}\mathrm{CH}_{2}\mathrm{OH}\) (propanol) - Covalent compound d. \(\mathrm{HClO}_{3}\) (chloric acid) - Strong acid e. \(\mathrm{CuSO}_4\) (copper sulfate) - Ionic salt f. \(\mathrm{C}_{12}\mathrm{H}_{22}\mathrm{O}_{11}\) (sucrose) - Covalent compound

Step 2: Classify solutions based on compound types

Using the information found in Step 1, we can now classify each solution: a. \(\mathrm{LiClO}_{4}\): As an ionic salt, this compound will fully dissociate into its constituent ions, making it a strong electrolyte. b. \(\mathrm{HClO}\): As a weak acid, this compound will partially dissociate into ions, making it a weak electrolyte. c. \(\mathrm{CH}_{3}\mathrm{CH}_{2}\mathrm{CH}_{2}\mathrm{OH}\) (propanol): As a covalent compound, this compound will not dissociate into ions, making it a nonelectrolyte. d. \(\mathrm{HClO}_{3}\): As a strong acid, this compound will fully dissociate into its constituent ions, making it a strong electrolyte. e. \(\mathrm{CuSO}_{4}\): As an ionic salt, this compound will fully dissociate into its constituent ions, making it a strong electrolyte. f. \(\mathrm{C}_{12}\mathrm{H}_{22}\mathrm{O}_{11}\) (sucrose): As a covalent compound, this compound will not dissociate into ions, making it a nonelectrolyte.

Step 3: Provide final classifications

From the classifications found in Step 2, we can provide the final classifications: a. \(\mathrm{LiClO}_{4}\): Strong electrolyte b. \(\mathrm{HClO}\): Weak electrolyte c. \(\mathrm{CH}_{3}\mathrm{CH}_{2}\mathrm{CH}_{2}\mathrm{OH}\) (propanol): Nonelectrolyte d. \(\mathrm{HClO}_{3}\): Strong electrolyte e. \(\mathrm{CuSO}_{4}\): Strong electrolyte f. \(\mathrm{C}_{12}\mathrm{H}_{22}\mathrm{O}_{11}\) (sucrose): Nonelectrolyte

Key Concepts

Ionic Compounds

Ionic compounds are substances composed of positive and negative ions held together by electrostatic forces, known as ionic bonds. These compounds, such as lithium perchlorate (\texttt{LiClO\(_4\)}) and copper sulfate (\texttt{CuSO\(_4\)}), are typically formed when a metal reacts with a nonmetal.

When ionic compounds dissolve in water, they dissociate into their constituent ions. This process enhances the solution's ability to conduct electricity, as the free ions move to the electrodes when an electric potential is applied. Hence, solutions containing dissolved ionic compounds are classified as strong electrolytes due to their high solution conductivity.

Acid-Base Chemistry

Acid-base chemistry is a fundamental concept involving the donation and acceptance of protons (hydrogen ions). Acids, like hypochlorous acid (\texttt{HClO}) and chloric acid (\texttt{HClO\(_3\)}), are proton donors, while bases are proton accepters. Acids are further classified as strong or weak based on their dissociation in water.

Strong acids, like chloric acid, dissociate completely, releasing a large number of hydrogen ions, hence being strong electrolytes. In contrast, weak acids, such as hypochlorous acid, only partially dissociate, leading to fewer free ions and classifying them as weak electrolytes. This partial dissociation characterizes weak acid solutions with moderate solution conductivity.

Solution Conductivity

Solution conductivity refers to the ability of an aqueous solution to conduct an electric current. It is a critical property that stems from the presence of free ions within the solution. Ionic compounds and strong acids, when dissolved in water, break down into cations and anions that can move freely, allowing for the flow of electricity.

For instance, lithium perchlorate and copper sulfate are strong electrolytes, providing high solution conductivity due to their full dissociation in water. Similarly, chloric acid is a strong acid that completely ionizes, resulting in a high concentration of ions and strong conductivity. However, weak acids like hypochlorous acid have fewer ions, resulting in lower conductivity.

Covalent Compounds

Covalent compounds, such as propanol (\texttt{CH\(_3\)CH\(_2\)CH\(_2\)OH}) and sucrose (\texttt{C\(_{12}\)H\(_{22}\)O\(_{11}\)}), are formed by sharing electrons between atoms, creating covalent bonds. Unlike ionic compounds, covalent compounds do not usually dissociate into ions in a solution.

As a result, they do not contribute to the solution's conductivity, classifying them as nonelectrolytes. This means that solutions containing covalent compounds like propanol and sucrose do not conduct electricity well, as there are no free ions to carry the current. Understanding the nature of covalent compounds helps us predict and explain the electrical properties of various solutions.