Exam 3 Study Guidance – Multiple Choice and Concepts

Q1. Which of the following compounds is INSOLUBLE in water? (Check all that apply.)

Background

Topic: Solubility Rules for Ionic Compounds

This question tests your understanding of how to use solubility rules to predict whether an ionic compound will dissolve in water.

Key Terms and Concepts:

• Soluble: A compound that dissolves in water to form a solution.

• Insoluble: A compound that does not dissolve significantly in water.

• Solubility Rules: Guidelines that help predict the solubility of ionic compounds in water. For example, most nitrates (NO3-) and alkali metal salts are soluble, while many carbonates (CO32-), phosphates (PO43-), and sulfides (S2-) are insoluble except with alkali metals or ammonium.

Step-by-Step Guidance

1. Review the solubility rules table provided in your exam materials. Focus on the rules for common anions (e.g., CO32-, SO42-, Cl-, etc.).

2. For each compound listed in the question, identify the cation and anion. For example, in CaCO3, Ca2+ is the cation and CO32- is the anion.

3. Apply the solubility rules to each compound. For instance, check if the anion is generally soluble or insoluble, and note any exceptions (e.g., "All carbonates are insoluble except those of alkali metals and ammonium").

4. Mark each compound as soluble or insoluble based on your analysis, but do not select the final answers yet.

Try solving on your own before revealing the answer!

Final Answer:

The compounds that are insoluble in water are: CaCO3 (calcium carbonate) and AgCl (silver chloride).

According to the solubility rules, most carbonates and chlorides are insoluble except for those with alkali metals or ammonium. CaCO3 and AgCl do not fall under the exceptions, so they are insoluble.