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Ch.4 - Reactions in Aqueous Solution
Chapter 4, Problem 38

Classify each of the following aqueous solutions as a nonelectrolyte, weak electrolyte, or strong electrolyte: (a) PbCl2 (b) N(CH3)3 (c) CsOH (d) H2S (e) CrCl2 (f) Ni(CH3COO)2.

Verified step by step guidance
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Step 1: Understand the definitions of electrolytes. A strong electrolyte completely dissociates into ions in solution, a weak electrolyte partially dissociates, and a nonelectrolyte does not dissociate into ions.
Step 2: Analyze each compound's chemical nature. Consider the solubility rules and the type of compound (ionic or molecular) to predict its behavior in water.
Step 3: For (a) PbCl2, check solubility rules. Lead(II) chloride is sparingly soluble, so it is a weak electrolyte.
Step 4: For (b) N(CH3)3, recognize it as a weak base (trimethylamine), which partially ionizes in water, making it a weak electrolyte.
Step 5: For (c) CsOH, identify it as a strong base (cesium hydroxide), which fully dissociates in water, classifying it as a strong electrolyte.

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Electrolytes

Electrolytes are substances that dissociate into ions when dissolved in water, allowing the solution to conduct electricity. They are classified into three categories: strong electrolytes, which completely dissociate into ions; weak electrolytes, which partially dissociate; and nonelectrolytes, which do not dissociate at all. Understanding the degree of ionization is crucial for classifying solutions.
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Strong Electrolytes

Strong electrolytes are compounds that fully dissociate into their constituent ions in an aqueous solution. Common examples include soluble salts like sodium chloride (NaCl) and strong bases like sodium hydroxide (NaOH). The complete ionization of strong electrolytes results in high electrical conductivity in the solution.
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Weak Electrolytes

Weak electrolytes are substances that only partially dissociate into ions in solution, resulting in a mixture of ionized and non-ionized molecules. Examples include weak acids like acetic acid (CH3COOH) and weak bases like ammonia (NH3). The limited ionization leads to lower conductivity compared to strong electrolytes.
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