Organic Chemistry -Solubility-Based
Methods
Test Study Guide:
-Distillation
Ch.12 Separations Chromatography
and Purifications -And More
CONCEPT SUMMARY
Solubility Based Methods
1. Extraction Process
Involves the combination of two immiscible liquids, where one liquid effectively dissolves the compound
of interest.
The polar layer, known as the aqueous phase, is primarily water and dissolves compounds that exhibit
hydrogen bonding or polarity.
The nonpolar layer, referred to as the organic phase, is capable of dissolving nonpolar compounds.
2. Separation Techniques
Extraction is performed using a separatory funnel, allowing for the collection of one phase while the other
remains in the funnel.
After separation, the solvent can be evaporated to isolate the desired compound.
3. Acid-Base Properties
The solubility of certain compounds can be enhanced by manipulating their acid-base properties.
4. Washing Technique
A wash serves as the reverse of extraction; it involves running a small amount of solvent over the
compound to dissolve impurities without removing the desired product.
5. Filtration Methods
Filtration is employed to separate solids from liquids:
i. Gravity Filtration: Utilized when the desired product is in the liquid filtrate; hot solvent is often used to
maintain solubility during this process.
ii. Vacuum Filtration: Applied when the solid product is of interest; this method uses vacuum pressure to
expedite filtration.
The above points summarize key concepts related to solubility-based methods in extraction and purification
processes.
Vacuum Filtration
A vacuum is utilized to expedite the solvent passage through the flask.
Recrystallization
The product is dissolved in a minimal volume of hot solvent.
Impurities, being more soluble, are excluded as crystals reform during cooling.
Distillation
Separates liquids based on boiling point differences; the lowest boiling point liquid vaporizes first and is
collected.
Simple Distillation: Applicable for liquids with boiling points under 150°C and at least 25°C apart.
Methods
Test Study Guide:
-Distillation
Ch.12 Separations Chromatography
and Purifications -And More
CONCEPT SUMMARY
Solubility Based Methods
1. Extraction Process
Involves the combination of two immiscible liquids, where one liquid effectively dissolves the compound
of interest.
The polar layer, known as the aqueous phase, is primarily water and dissolves compounds that exhibit
hydrogen bonding or polarity.
The nonpolar layer, referred to as the organic phase, is capable of dissolving nonpolar compounds.
2. Separation Techniques
Extraction is performed using a separatory funnel, allowing for the collection of one phase while the other
remains in the funnel.
After separation, the solvent can be evaporated to isolate the desired compound.
3. Acid-Base Properties
The solubility of certain compounds can be enhanced by manipulating their acid-base properties.
4. Washing Technique
A wash serves as the reverse of extraction; it involves running a small amount of solvent over the
compound to dissolve impurities without removing the desired product.
5. Filtration Methods
Filtration is employed to separate solids from liquids:
i. Gravity Filtration: Utilized when the desired product is in the liquid filtrate; hot solvent is often used to
maintain solubility during this process.
ii. Vacuum Filtration: Applied when the solid product is of interest; this method uses vacuum pressure to
expedite filtration.
The above points summarize key concepts related to solubility-based methods in extraction and purification
processes.
Vacuum Filtration
A vacuum is utilized to expedite the solvent passage through the flask.
Recrystallization
The product is dissolved in a minimal volume of hot solvent.
Impurities, being more soluble, are excluded as crystals reform during cooling.
Distillation
Separates liquids based on boiling point differences; the lowest boiling point liquid vaporizes first and is
collected.
Simple Distillation: Applicable for liquids with boiling points under 150°C and at least 25°C apart.
