Reactions in Aqueous Solutions

Lesson Overview

• Reactions in Aqueous Solutions

Focus Question

• Unique aspects of reactions in water.

Vocabulary

• Aqueous solution: mixture in water.

• Solute: substances dissolved in a solvent.

• Solvent: the substance in which solutes are dissolved (water).

• Complete ionic equation: shows all particles in solution.

• Spectator ion: ions that do not participate in reactions.

• Net ionic equation: includes only particles involved in reactions.

Aqueous Solutions

• Formed when substances dissolve in water.

• Solutes can be molecular compounds like sugar or ions from ionic compounds.

• Acids produce hydrogen ions in solutions.

Types of Reactions

Double-Replacement Reactions

• Reactions involve two aqueous solutions with ions.

• Products may include a precipitate, water, or gas.

Reactions that Form Precipitates

• Example: NaOH + CuCl₂ → NaCl + Cu(OH)₂.

• Complete ionic equation shows separate ions.

• Spectator ions are excluded in net ionic equations:

  • Net ionic: 2OH⁻ + Cu²⁺ → Cu(OH)₂.

Reactions that Form Water

• Example: HBr + NaOH → H₂O + NaBr.

• Net ionic focuses on reactive species: H⁺ + OH⁻ → H₂O.

Reactions that Form Gases

• Common gases: CO₂, H₂S.

• Example: 2HI + Li₂S → H₂S + 2LiI.

• Simplified to net ionic: 2H⁺ + S²⁻ → H₂S.

Overall Equations

• Can combine multiple reactions into a single chemical equation.

Quizzes

• Review of key concepts about ions, chemical equations, and properties of solutions.