Alkyl halides, also known as haloalkanes or halogenoalkanes, are organic compounds containing one or more halogen atoms (fluorine, chlorine, bromine, or iodine) bonded to carbon atoms within an alkyl group. They are versatile compounds with various industrial, pharmaceutical, and laboratory applications. Types and Classification Alkyl halides can be classified based on two main criteria: the … Read more
Measurement of Surface can be measured using various techniques, each based on different physical principles. Below are the commonly used methods: 1. Capillary Rise Method for Measurement of Surface and Interfacial Tensions Principle: This method relies on the height a liquid rises in a capillary tube due to surface tension. The liquid rises because of adhesive … Read more
Definition of Hydrophile-Lipophile Balance Scale The HLB scale is a numerical system that indicates the balance between the hydrophilic and lipophilic portions of a surfactant molecule. Scale Range: 0 (completely lipophilic) to 20 (completely hydrophilic). Calculation of Hydrophile-Lipophile Balance Scale For nonionic surfactants: $\text{HLB} = 20 \times \frac{M_{\text{hydrophilic}}}{M_{\text{total}}}$ where: is the molecular mass of the … Read more
Definition of Adsorption at Solid Interfaces Adsorptions at solid interfaces involves the accumulation of molecules from a liquid or gas onto a solid surface. Types of Adsorption: Physical Adsorption (Physisorption) Forces: Weak van der Waals forces; reversible. Characteristics: Occurs at low temperatures; decreases with heat. Forms multilayers as molecules are loosely held. Example: Adsorption of … Read more
Definition of Detergency Detergency is the process by which surfactants clean surfaces by removing dirt, oils, and other contaminants. Mechanism Wetting: Surfactants lower surface tension, allowing cleaning solutions to spread. Emulsification: Oils and greases are emulsified and suspended. Dispersion: Particulate soils are dispersed and prevented from re-deposition. Factors Influencing Detergency Surfactant Concentration: Must be above … Read more
Definition of Solubilization Solubilization is the process of dissolving a solute into a solvent with the aid of surfactants, forming a thermodynamically stable isotropic solution. Mechanism Micellar Solubilization: Incorporation of hydrophobic solute molecules into the hydrophobic core of micelles. Phase Behavior: Surfactants above the CMC facilitate solubilization. Factors Affecting Solubilization Surfactant Structure: Tail length and … Read more
Definition of Surfactants Surfactants are compounds that reduce surface and interfacial tensions by concentrating at the interface due to their amphiphilic nature. Classification of Surfactant Anionic Surfactants Charge: Negative in water. Functional Groups: Sulfate, sulfonate, or carboxylate. Example: Sodium lauryl sulfate (SLS) – used in shampoos, toothpaste, detergents. Characteristics: High detergency and foaming; can be … Read more
Biomolecules are organic molecules produced by living organisms, essential for the structure, function, and regulation of cells, tissues, and organs. They sustain biological processes and can be classified into four major categories: carbohydrates, lipids, proteins, and nucleic acids. Carbohydrates in Biomolecules Structure: Composed of carbon (C), hydrogen (H), and oxygen (O) in a 1:2:1 Includes … Read more
Amphetamine Definition Amphetamine is a powerful central nervous system stimulant that affects chemicals in the brain and nerves contributing to hyperactivity and impulse control. It is commonly used in the treatment of attention-deficit hyperactivity disorder (ADHD) and narcolepsy, under brand names like Adderall and Dexedrine. Structure: Chemical Formula: C₉H₁₃N Molecular Structure: Contains a benzene ring … Read more
Ethylenediamine Definition Ethylenediamine is a bifunctional amine consisting of two amino groups (-NH₂) attached to a two-carbon ethylene chain. It serves as a chelating agent, corrosion inhibitor, and precursor to many industrial chemicals, such as ethylenediaminetetraacetic acid (EDTA). Structure: Chemical Formula: C₂H₈N₂ Molecular Structure: Consists of a two-carbon chain with an amino group (-NH₂) attached … Read more
