University:
University of North Carolina at Charlotte
Course:
CHEM 1251 | General Chemistry I
Academic year:

2024
Views:

474

Pages:

3
Author:

Kamila P.

Title: CHEMICAL REACTIONS IN AQUEOUS SOLUTIONS Subsection: For a solute to dissolve in a solvent, the solvent-solute interaction must be stronger than the solute-solute interaction. Ionic Compounds: NaCl(s) → Na+(aq) + Cl-(aq) An IONIC COMPOUND dissociates (separates its ions) when it dissolves. Molecular Compounds: Molecular compounds do NOT dissociate (separate) when they dissolve. (ACID EXCEPTION) ACIDS - MOLECULAR ELECTROLYTES ACIDS are molecular compounds that ionize to form H+ ions when they dissolve in water. ACID STRENGTH is determined by the ease with which the H+ ion dissociates. This is how to identify hydrochloric acid: HCl(aq) → H+(aq) + Cl-(aq). ELECTROLYTES and NONELECTROLYTES Electrolytes dissolve in water to form a solution that will CONDUCT ELECTRICITY. You need IONS to CONDUCT ELECTRICITY. Nonelectrolytes dissolve in water to form a solution that will NOT CONDUCT ELECTRICITY. (NO IONS!) Examples: Ionic Compounds: NaCl(s) → Na+(aq) + Cl-(aq) Acids: HCl(aq) → H+(aq) + Cl-(aq) Molecular Compounds: C6H12O6(s) → C6H12O6(aq) Weak Acids: CH3COOH(aq) → H+(aq) + CH3COO-(aq) Strong Acids: HNO3(aq) → H+(aq) + NO3-(aq) H2SO4(aq) → H+(aq) + HSO4-(aq) Paragraph: When an ionic compound (like CaCl₂) dissolves in water, what is actually in the resulting solution? Equation: CaCl₂(s) → Ca²⁺(aq) + 2Cl⁻(aq) Note: Not all ionic compounds dissolve in water. Ex: AgCl in water (insoluble) Definitions: Soluble: Dissolves in water completely Insoluble: Does NOT dissolve in water Solubility Rules: (look at exam information sheet!) A lot of factors affect whether an ionic compound will be soluble in water. Practice: PbCl₂ (insoluble) CuCl₂ (soluble) → Cu²⁺(aq) + 2Cl⁻(aq) Ca(NO₃)₂ (soluble) → Ca²⁺(aq) + 2NO₃⁻(aq) BaSO₄ (insoluble) NiS (insoluble) Li₂CO₃ (soluble) → 2Li⁺(aq) + CO₃²⁻(aq)