Applied Chemistry
- How is the calorific value of a solid fuel determined using a bomb calorimeter? In one line A known mass of fuel is burnt in excess oxygen inside a sealed steel "bomb" placed in a known mass of water, and the rise in wat... 1
- How does Boys' gas calorimeter measure the calorific value of a gaseous fuel? In one line A known volume of gas is burnt at a steady rate, and its heat is absorbed by water flowing through cooling tubes; from the water... 1
- How do you calculate the calorific value of coal using Dulong's formula? In one line Dulong's formula estimates the higher calorific value of a fuel from its percentages of carbon, hydrogen, oxygen and sulphur (fr... 1
- How do you calculate the minimum weight of oxygen and air needed to burn 1 kg of coal? In one line Using balanced combustion equations, find the oxygen needed by C, H and S, subtract the oxygen already present in the fuel, and... 1
- What is proximate analysis of coal and why do moisture, volatile matter, ash and fixed carbon matter? In one line Proximate analysis finds the percentages of moisture, volatile matter, ash and fixed carbon in coal by simple weighing and heati... 1
- How do you find the volume of air at STP needed to burn coal, including excess air? In one line Convert the minimum mass of oxygen into moles, multiply by 22.4 to get its volume at STP, then divide by 0.21 because air contai... 1
- What is ultimate analysis of coal and how are carbon, hydrogen, nitrogen, sulphur and oxygen found? In one line Ultimate analysis determines the elemental composition of coal (C, H, N, S, ash and O by difference) and is used for calorific v... 1
- What are polymers and macromolecules, and what do monomer and degree of polymerisation mean? In one line A polymer is a macromolecule (very large molecule, molecular weight typically 10³ to 10⁷) built by joining many small repeating... 1
- What chemical bonds and intermolecular forces hold polymer chains together? In one line Atoms within a polymer chain are joined by strong primary covalent bonds, while separate chains are held together by weaker seco... 1
- An alloy of Cd and Bi contain 25% of Cd Find the mass of eutectic in 1kg of solid Alloy, if the eutectic contains 40 % of Cd. Given: the alloy has 25% Cd (75% Bi), and the eutectic has 40% Cd (60% Bi). The alloy has less Cd (25%) than the eutectic (40%), so it has e... 1
- How material selection and proper design of equipments can prevent corrosion. Explain with the help of diagram and designing principles. 1. Proper selection of material Use noble or corrosion-resistant metals (Pt, Au, Ti) or alloys such as stainless steel and cupronickel where... 1
- A sample of coal has the following composition C = 84 %, O = 8.4 %, H = 5.5 %, S = 1.5%, N = 0.6 %, Calculate the higher and lower calorific values of coal. Given: C = 84%, H = 5.5%, O = 8.4%, S = 1.5%, N = 0.6% (N does not contribute to the heat). Dulong's formula (C, H, O, S in %): HCV = 1/100[... 1
- Explain fiber reinforced composite and write its applications and limitations. Fibre-reinforced composites (FRC) are composites in which the dispersed phase is in the form of fibres, i.e. long, thin filaments with a hig... 1
- Why are alloys preferred over pure metals in many applications? Pure metals are generally soft, ductile, of low strength, easily corroded and hard to cast. Alloying improves these properties, so alloys ar... 1
- What is condensed phase rule equation? Write merits and limitation of phase rule. Condensed (reduced) phase rule: the phase rule is F = C − P + 2. For solid–liquid equilibria such as alloys, the vapour phase is practically... 1
- Distinguish between galvanizing and tinning. GalvanizingTinning Iron or steel is coated with zinc, usually by dipping in molten Zn at about 450 °C.Iron or steel is coated with tin, usua... 1
- How do following factors affects the rate of corrosion i) PH medium ii) Purity of metal iii) Area of anode and cathode. i) pH of the medium: the rate of corrosion generally rises as pH falls, because acidic media supply H⁺ for the cathodic reaction (2H⁺ + 2e⁻... 1
- What are advantages of gaseous fuels over solid and liquid fuels? They can be carried easily through pipelines to the point of use, so there is no handling or storage labour. They mix intimately with air, s... 1
- 1 gm. of coal sample was used for determination of nitrogen. The ammonia evolved was passed into 50ml of 0.1 N H2SO4, the excess acid required 42 ml. of 0.1N NaOH for neutralization Calculate % of N. Given: W = 1 g; acid taken = 50 mL of 0.1 N H₂SO₄; excess acid = 42 mL of 0.1 N NaOH. Volume of 0.1 N acid used by NH₃ = 50 − 42 = 8 mL. %N... 1
- Explain the determination of sulphur present in coal sample and write its significance. Principle: the sulphur in coal is converted to sulphate and weighed as BaSO₄. Procedure A known mass (W g) of coal is burnt in a bomb calori... 1
- What is supercritical CO2 and how does it differ from liquid and gaseous CO2. Supercritical CO₂ (scCO₂) is CO₂ held above its critical temperature (T_c = 31.1 °C) and critical pressure (P_c = 72.8 atm ≈ 7.38 MPa). Abov... 1
- Write an informative note on biodiesel. Biodiesel is a mixture of mono-alkyl (methyl or ethyl) esters of long-chain fatty acids. It is made from vegetable oils (jatropha, karanja,... 1
- Explain synthesis of Adipic acid by traditional and green pathway. Also write the principle of green chemistry involved in this reaction. Conventional (traditional) route C₆H₆ xrightarrow[Ni / Pt]3H₂ undersetcyclohexanemathrmC₆H₁₂ xrightarrow[Co catalyst]O₂\ (air) undersetcyclo... 1
- Define Matrix phase and dispersed phase of composites. A composite has two constituents: 1. Matrix phase – the continuous phase that surrounds and binds the other phase. It may be a polymer, meta... 1