Applied Chemistry
- What is green chemistry and how is atom economy used to compare conventional and green routes? In one line Green chemistry is the design of chemical products and processes that reduce or eliminate the use and generation of hazardous su... 1
- How does the green biotechnological synthesis of indigo dye compare with the conventional chemical route? In one line Conventionally, indigo is made from aniline, formaldehyde and hydrogen cyanide using strong alkali at high temperature, while th... 1
- How is adipic acid made conventionally and by the green route, and why is the green route better? In one line Adipic acid is conventionally made from benzene via cyclohexanol/cyclohexanone oxidation with nitric acid, which releases the gr... 1
- How does the green synthesis of carbaryl avoid methyl isocyanate, the chemical behind the Bhopal tragedy? In one line Conventionally, the insecticide carbaryl is made by reacting 1-naphthol with methyl isocyanate (MIC), whereas the greener route... 1
- What are supercritical fluids like supercritical CO2, and why are they used as green solvents? In one line A supercritical fluid is a substance above its critical temperature and critical pressure, where it has liquid-like density (dis... 1
- What are ionic liquids and why are they called green, designer solvents? In one line Ionic liquids are salts that are liquid below 100 °C (many at room temperature), made of bulky organic cations and inorganic or... 1
- How is biodiesel synthesised by transesterification and what are its advantages as a green fuel? In one line Biodiesel is a mixture of fatty acid methyl (or ethyl) esters made by transesterification of vegetable oils or animal fats with... 1
- How is ethanol produced by fermentation and why is it considered a green fuel? In one line Fuel ethanol is produced by yeast fermentation of sugars from molasses, sugarcane juice, grains or biomass, followed by distilla... 1
- What is a composite material and what characteristics make composites useful in engineering? In one line A composite is a multiphase material made by combining two or more chemically and physically different constituents, separated b... 1
- What is the matrix phase in a composite and what functions does it perform? In one line The matrix is the continuous phase of a composite that surrounds and binds the dispersed phase, transfers load to it, protects i... 1
- What is the dispersed (reinforcing) phase in a composite and what are its functions? In one line The dispersed phase is the discontinuous phase (fibres, particles, flakes) embedded in the matrix that mainly carries the load a... 1
- How are composites classified based on the type of reinforcement used? In one line Based on the reinforcement, composites are classified into particle-reinforced, fibre-reinforced and structural composites, each... 1
- How are composites classified by matrix as polymer, metal and ceramic matrix composites? In one line Based on the matrix material, composites are classified as polymer matrix composites (PMC), metal matrix composites (MMC) and ce... 1
- What are fibre-reinforced composites and why does fibre length and orientation matter? In one line Fibre-reinforced composites contain strong, stiff fibres embedded in a matrix; their strength depends heavily on fibre length, o... 1
- What are structural composites like laminates and sandwich panels, and why are they so stiff yet light? In one line Structural composites are made of layers or of face sheets and a core bonded together, and their properties depend on the geomet... 1
- What is the difference between thermoplastic and thermosetting polymers? In one line Thermoplastics soften on heating and harden on cooling repeatedly because their linear chains are held by weak forces, while the... 1
- How are polymers classified by origin, structure, polymerisation type and composition? In one line Polymers are classified in several ways: by source (natural, semi-synthetic, synthetic), by chain structure (linear, branched, c... 1
- What are number average and weight average molecular weights of a polymer and what is polydispersity? In one line Because a polymer sample contains chains of many different lengths, its molecular weight is expressed as an average: the number... 1
- How do you calculate number average and weight average molecular weight in a numerical? In one line Make a table of N_i, M_i, N_iM_i and N_iM_i², then use M_n = ΣN_iM_i/ΣN_i and M_w = ΣN_iM_i²/ΣN_iM_i. Explained simply The metho... 1
- What is the difference between crystalline and amorphous polymers, and what controls crystallinity? In one line In crystalline regions polymer chains are packed in an ordered, regular way, while in amorphous regions they are randomly coiled... 1
- What is the glass transition temperature of a polymer and what factors affect it? In one line The glass transition temperature (T_g) is the temperature below which an amorphous polymer is hard, rigid and glassy, and above... 1
- What do hardness, tensile strength, creep, fatigue and impact resistance mean for polymers? In one line These mechanical properties describe how a polymer responds to force: resistance to indentation (hardness), maximum pulling stre... 1
- Why are polymers good electrical insulators, and what are dielectric strength, insulation resistance and surface resistivity? In one line Most polymers have no free electrons or ions, so they resist current flow; their insulating quality is described by dielectric s... 1
- What optical properties of polymers matter: refractive index, transmittance, photoelectric property and colour? In one line Optical properties describe how a polymer interacts with light: how much it bends light (refractive index), how much light passe... 1