Chemistry Unit-IV: Non Aqueous Solvents

Non-Aqueous Solvents

• Classification of solvents based on polarity and ionization capabilities.
• Ionizing solvents exhibit specific properties affecting solute interactions.

Liquid Ammonia (NH3)

• Exhibits unique physical properties influencing its solvation abilities.
• Undergoes auto-ionization leading to unique acid-base behavior.
• Functions as a proton acceptor, facilitating various acid-base reactions.
• Engages in precipitation reactions and complex formation.
• Capable of ammonolysis, utilizing ammonia in chemical reactions.
• Metal-ammonia solutions allow for diverse reactions, including redox processes.
• Advantages include high dielectric constant; disadvantages involve handling and toxicity concerns.

Liquid SO2

• Characterized by distinct physical properties impacting its solvation characteristics.
• Exhibits solubility for a range of inorganic and organic substances.
• Electrolytic conductance indicates behavior of dissolved ions in the solvent.
• Supports acid-base reactions, solvolysis, and precipitation.
• Facilitates complex formations and reduction-oxidation (redox) reactions.

Liquid HF

• Displays specific physical properties that influence its effectiveness as a solvent.
• Demonstrates solvent effects in various chemical reactions.
• Exhibits amphoteric behavior, allowing it to act as both an acid and a base.
• Engages in precipitation reactions, demonstrating versatility in chemical processes.
• Involved in redox reactions and solutions of biologically relevant compounds.

Acids - Bases

• Bronsted-Lowry Concept: Defines acids as proton donors and bases as proton acceptors; assesses relative strength within this framework.

• Lewis Concept: Classifies acids and bases as electron pair acceptors (acids) and donors (bases).

• Hard and Soft Acids and Bases (HSAB): Classifies species based on size and charge; hard acids and bases prefer interactions, while soft acids and bases engage differently.

• Pearson's HSAB Principle: States that hard acids preferentially bond with hard bases and soft acids with soft bases, guiding predictions in chemical reactions.

• Applications and Limitations: Useful in predicting reactivity patterns but may not account for all behaviors in complex systems.