orgo final summary sheet

Safety

  • Personal Protective Equipment (PPE)

    • Essential for laboratory safety.

    • Designed to protect wearers from safety hazards.

    • Includes items like safety glasses and gloves.

Eye Protection

  • Safety glasses must:

    • Form a seal around the eyes.

    • Prevent entry of liquids or solids.

    • Features include:

      • Impact-resistant lenses.

      • Articulated brow.

      • Side splash guards.

Gloves

  • Made from various materials to interact differently with compounds.

Proper Attire

  • Non-woven closed toe shoes recommended.

Safety Equipment

  • For small fires in beakers, cover container with a non-flammable object (like a watch glass) to extinguish flames.

Laboratory Glassware

Ground Glass Joints

  • Creates a gas-tight seal when assembled.

  • Standard taper joint specifications:

    • Example: 19/22 → 19 mm wide, 22 mm tall.

Beakers and Flasks

  • Used for transferring liquids and solutions, heating, and reactions.

  • Not suitable for precise volume measurements.

  • Erlenmeyer Flasks:

    • Conical with a flat bottom.

    • Prevents evaporation and allows swirling.

    • Filter Flask:

      • Thicker glass for evacuation with hose barb attachment.

    • Round-Bottomed Flasks:

      • Spherical, for easy stirring and even heating.

      • Not to be heated with hot plates.

    • Three-Necked Flasks:

      • Evacuated like round-bottom flasks with multiple ports for apparatus attachment.

Adapters and Connectors

  • Claissen Adapter: Upward U-shaped, splits joint into two ports.

  • Three-way Adapter: Splits the joint in two directions, one for the condenser.

  • Vacuum Adapter: Incorporates hose for vacuum applications.

  • Inlet Adapter: Connects apparatus to gas or vacuum line.

Funnels

  • Wide-Mouth Funnels: For transferring dry powders or viscous liquids.

  • Glass Funnels: Used for gravity filtration with filter paper.

  • Buchner Funnels: Cylindrical ceramic for suction filtration.

  • Separatory Funnels: Conical with a stopcock for liquid separation.

Condensers

  • Reflux Condensers/Fractionating Columns: Used to condense vapor during boiling.

  • West Condensers: Slim design for promoting collection of condensed liquids.

Chemical Waste Classifications

Halogenated Organics

  • Contains covalently-bonded halogens (e.g., Chloroform, CHCl3).

Non-Halogenated Organics

  • Organic compounds without covalently bonded halogens (e.g., Ethanol, CH3CH2OH).

Acidic Aqueous

  • Aqueous solutions with inorganic materials (e.g., Aqueous hydrochloric acid, H2O + HCl).

Solids

  • Solid waste without halogens (e.g., Fluorene, C13H12).

Waste Hierarchy

  • Treat mixtures as the most dangerous component; halogenated organics have the highest hazard potential.

Recrystallization and Melting Points

Background

  • Recrystallization purifies substances by dissolving in a solvent and then precipitating refined crystals.

  • Historical Context: Indian techniques in sugar production date back to the 4th century A.D.

Theory

  • Crude compounds require purification.

  • Impurities affect the free energy and melting point.

Steps in Recrystallization

  • Use of suitable solvents selected for specific boiling and solubility properties.

  • Slow cooling is essential for high purity crystal formation.

  • Employ techniques such as scratching or adding seed crystals to induce crystallization.

  • Purified solids undergo filtration and are washed to remove impurities.

Thermodynamics of Melting

  • Melting point depression caused by impurities leads to broader melting ranges.

  • Eutectic points define the lowest melting points in binary mixtures.

Procedure for Recrystallization

  • Boil impure solids in water, slow cooling in an ice bath if necessary.

  • Use vacuum filtration for drying samples.

Distillation

Background

  • Technique to separate based on volatility (Raoult's Law, Dalton’s Law, Ideal Gas Law).

  • Distillation can be simple or fractional.

Concepts

  • Azeotropes hinder successful separation, representing mixtures where vapor and liquid compositions match.

TLC and Rotary Evaporation

Techniques

  • Utilizes chromatography for separation based on polarity, with TLC employing polar stationary phases and nonpolar mobile phases.

  • Rotary evaporation effectively concentrates materials by removing solvents.

Liquid-Liquid Extraction

Process

  • Separation based on solubility in immiscible liquids, characterized by partition coefficients.

  • Importance of pH in managing the charge states of compounds.

Techniques

  • Agitation increases contact area for extraction but must be vented to release gas pressure.

  • Centrifugation may aid in separating emulsified layers if needed.

Column Chromatography

Overview

  • Ideal for larger quantities.

  • Relies on gravity; stationary and mobile phases remain the same concepts as TLC.

Packing and Running Columns

  • Use of appropriate materials to prevent solid loss during operation, including gas wool or cotton and sand layers.

  • Techniques for establishing uniformity in column packing.

  • Monitoring progression through visual observation or TLC analysis.