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Chemical Engineering
Chemical Engineering is the branch of engineering that deals with the technology of large-scale chemical production and the manufacture of products through chemical processes. Today, the field of chemical engineering is a diverse one, covering areas from biotechnology and nanotechnology to mineral processing.
1,464 Questions
What is the purpose of correlation charts in FT-IR?
1. The purpose of correlation chart are to measure or relate two variables and allow us to make a prediction about one variable based on what we know about another variable. For example, a correlation between the 2 known sample.
Is it true that a low density gas must be hot in order to produce an absorption line?
No, a low-density gas does not need to be hot in order to produce an absorption line. Absorption lines are formed when atoms in a gas absorb specific wavelengths of light. The presence of these lines does not depend on the temperature of the gas, but rather on the composition and energy levels of the atoms within the gas.
What are chemical information sources?
Chemical information sources are resources that provide data and knowledge about chemicals and their properties. This can include databases, journals, textbooks, and websites that offer information on chemical structures, properties, reactions, and uses. These sources are crucial for researchers, students, and professionals working in chemistry and related fields.
What are Antoine coefficients for CH4?
(Source Introduction to Chemical Engineering Thermodynamics 7th ed by J.M. Smith, p.682)
Effect of height on volumetric flow rate?
The volumetric flow rate through a pipe is not directly affected by the height difference between two points in the system. Volumetric flow rate is primarily influenced by factors such as pressure difference, pipe diameter, fluid viscosity, and fluid density. However, height difference can affect the pressure head in the system, which in turn can impact the flow rate through the pipe.
What is the significance of transfatty acids in oils?
The significance of transfatty acids in oils is that we cannot metabolize them. Their counterpart is "cis fats", which are curled, but trans fats are straight. Since they aren't metabolized, they're stored in low-density lipids (LDL) -- the "bad" kind of triglycerides on the doctor's lab reports -- which leads to artery disease, heart attacks and strokes.
What type of bond holds nylon?
Nylon is held together by covalent bonds, which are strong bonds formed by sharing electrons between atoms. These bonds form a large and stable polymer structure in nylon.
Mooney viscosity refers to a measurement of the viscosity of a rubber compound in a heated state. It is commonly used to evaluate the processability of rubber materials and to assess the degree of polymer chain scission or crosslinking that has occurred during compounding or processing. The measurement is typically done using a Mooney viscometer.
What is the main difference between polyamide and polysulfone?
A polyamide is a polymer containing monomers of amides. (nitrogen)
A polysulfone contains the subunit aryl-SO2-aryl, the defining feature of which is the sulfone group. (sulfur)
Neem oil is extracted from the seeds of the neem tree through a process called cold-pressing. The seeds are crushed to release the oil, which is then filtered and purified to remove impurities. This method ensures that the oil retains its natural properties and benefits.
What is difference between ion exchange and adsorption?
Ion exchange itself is an adsorption reaction too. The question is probably about the difference between ion exchange and specific sorption.
In ion exchange, an ion sorbs to the surface by removing an other ion of the same valence or multiple ions of lower valence. In this way, ion exchange never changes the surface charge.
Specific sorption describes the inner sphere complexing of an ion to the surface without the need for other ions to be removed. In this way, specific sorption is able to alter the surface charge.
Yes, tin, Sn (Stannum), is a pure metal element, atom number 50 in the Periodic Table.
Crude oil is typically stored underground where temperatures are relatively constant, so it is not inherently hot. However, during extraction and transportation, friction and pressure can cause the oil to heat up.
Heat transfer takes place as per which thermodynamics?
Heat transfer generally follows the laws of thermodynamics, including the first law (conservation of energy) and the second law (entropy). Heat transfer can occur through conduction, convection, or radiation, with the direction of heat flow determined by temperature differences and the properties of the materials involved.
What is the function of matrix phase in composites?
1. To bind the fibers together so that the applied stress is distributed among the fibers
2. To protect the surface of the fibers from being damaged
3. To separate the fibers and inhibit crack propagation
Cerium is commonly used in catalytic converters to reduce emissions in vehicles. It is also used in glass polishing and as a component in some types of glass, such as camera lenses. Additionally, cerium is used in the production of certain types of alloys and as a catalyst in organic synthesis reactions.
Which ion of iron is present in the formula Fe2O3?
In the formula Fe2O3, the iron ion present is Fe3+. This means that each iron ion has a +3 charge, which balances with the -2 charge on each oxygen ion in the compound.
Methods of separation of isomers of pentane?
Isomers of pentane can be separated using techniques such as fractional distillation, gas chromatography, and crystallization. Fractional distillation exploits the difference in boiling points between isomers to separate them based on their vapor pressures. Gas chromatography separates isomers based on differences in their affinity for the stationary phase. Crystallization can also be used to separate isomers by inducing the formation of different crystal structures.
What is the fullform of DCDA process for manufacturing of sulfuricacid?
The full form of DCDA process is Double Contact Double Absorption process for the manufacturing of sulfuric acid. In this process, the sulfur dioxide gas is reacted with air to form sulfur trioxide, which is then absorbed in water to produce sulfuric acid. The double contact and double absorption steps enhance the overall efficiency of the sulfuric acid production.
What unit operations are used in dye manufacturing?
All synthetic organic dyes and pigments contain a ring structure of atoms. The same formation is present in dye intermediates. It is usual also for the dye intermediate to have one or more of the groups of atoms that react chemically to form salts.
A simple example of an intermediate is -naphthol, which is obtained from naphthalene by heating it with 96 percent sulfuric acid at 160 C (320 F), adding sodium sulfate, and volatizing the remaining naphthalene with steam. Sodium naphthalene-2-sulfonate, left behind after this steam treatment, is then fused with caustic soda to yield -naphthol. The -naphthol is separated from the mixture by diluting it with water and treating it with sulfuric acid. These reactions, known respectively as sulfonation and alkali fusion, are given the name unit processes.
A number of such unit processes are available to the chemical manufacturers, and by means of various permutations, it is possible to synthesize the several hundred intermediates needed for the manufacture of the modern range of colorants.
Nitration.In nitration, a nitro group is substituted for a hydrogen atom in an aromatic hydrocarbon molecule by the action of nitric acid. Benzene yields nitrobenzene by reaction with a mixture of nitric and sulfuric acids at a temperature not exceeding 50 C (122 F). Toluene, with mixed acid at 30-35 C (86-95 F), yields orthonitrotoluene, metanitrotoluene, and paranitrotoluene. Technical quality nitrotoluenes are obtained from the crude nitration product by physical separation methods including fractional distillation; 1-nitronaphthalene is obtained when naphthalene is nitrated.Nitration is a strongly exothermic, or heat-releasing, reaction; in large-scale nitrations the temperature must be maintained between established limits and efficient means of cooling provided. Cast-iron, mild steel, or stainless-steel vessels are used, arranged to permit agitating the mixture. The addition of nitric acid is carefully controlled by instruments that detect incipient rises in temperature. Other safeguards stop the addition in case the stirring mechanism is halted by a power or mechanical failure.
Reduction.Amines, chemical compounds formed by substituting organic radicals for the hydrogen atoms of ammonia, may be obtained from nitro compounds by reduction; that is, replacement of oxygen by hydrogen. This is accomplished by mixing the nitro compound with iron borings and a minimum quantity of aqueous hydrochloric acid in a cast-iron reducer with a powerful agitator. The end products are aniline, or other amines, and ferric oxide. The aniline, which separates as an upper layer above the aqueous suspension of iron and oxide, is removed mechanically and purified by steam distillation followed by fractionation. Analogous processes are employed in making other amines from their corresponding nitro compounds. Halogenation.Halogenation is the introduction, by direct or indirect means, of a halogen (fluorine, chlorine, or bromine) into molecules of dye intermediates. In many cases direct substitution can be effected using elemental chlorine or bromine with or without a catalyst. In other cases a diazotized amine is treated with cuprous chloride or bromide. Indirect means must be employed for introducing fluorine. Hydrogen fluoride (HF), for example, is used to displace chlorine in chloro compounds. Amination.The amination, or conversion of chloro compounds to amines, can be accomplished by ammonolysis, a process that involves heating the chloro compound with aqueous ammonia in a steel autoclave (equipment for working at pressures above atmospheric). Chloronitrobenzene, for example, is transformed into nitroaniline by this process. Several industrial amination processes exist. In the Dow Process monochlorobenzene is converted into aniline by heating it with aqueous ammonia at 240 C (464 F) in the presence of a copper oxide catalyst. In the Halcon Process phenol undergoes ammonolysis to yield aniline. Hydroxylation.Hydroxylation is the introduction of a hydroxyl, or OH, group into the dye-intermediate molecule. Among the methods used for this are fusion by sodium hydroxide, Bucherer reaction (conversion of aromatic amines into phenolic compounds by aqueous sulfite or bisulfite), hydrolysis of chloro compounds under various reaction conditions according to the reactivity of the chloro compound, decomposition of diazonium salts by hot aqueous sulfuric acid, hydrolysis of sulfo groups, and oxidation (described below); for example, the compound cumene yields phenol and acetone. Oxidation.Oxidation, the combination of a substance with oxygen, or, generally, any reaction in which an atom loses electrons, is a ubiquitous chemical reaction in dye chemistry; only a few examples can be given here. The conversion of methyl groups into carboxylic acids, and more especially into styryl compounds, is effected by various oxidants such as sodium hypochlorite, potassium permanganate, and sodium dichromate. The catalyzed oxidation of naphthalene with air leads to phthalic anhydride. Other important reactions include oxidation of leuco compounds to dyes and the formation of complex polycyclic substances from simpler molecules. Benzidine rearrangement.The benzidine rearrangement consists of the conversion of nitrobenzene and its derivatives into derivatives of biphenyl in a two-stage process. The first stage consists of alkaline reduction with zinc dust to the hydrazobenzene; and the second of treatment with hydrochloric acid.The above and other unit processes are used in various combinations in order to produce the important intermediate chemicals that are, in turn, used to manufacture the dyes themselves.
H Acid.H Acid, which is 1-amino-8-hydroxynaphthalene-3,6-disulfonic acid, an important dye intermediate, is produced from naphthalene by a combination of the unit processes of sulfonation, nitration, reduction, and hydrolysis. H Acid is used in the manufacture of a large number of azo dyes. Diaminostilbene disulfonic acid.4,4'-diaminostilbene-2,2'-disulfonic acid is produced from p-nitrotoluene by a combination of the unit processes of sulfonation, oxidation, and reduction. This product is used in large quantities for manufacture of fluorescent brightening agents.Why corrosion is faster at joints?
Corrosion at joints occurs faster due to increased exposure to moisture and other corrosive elements. Joints often have crevices or imperfections where moisture can collect, creating an ideal environment for corrosion to accelerate. Additionally, joints may experience increased stress or movement, which can break down protective coatings and expose the metal to corrosion.
What evidence did you observe that oxygen is not very soluble in water?
Oxygen's low solubility in water is evidenced by the fact that oxygen concentrations in water are relatively low compared to other gases like nitrogen. Additionally, the solubility of oxygen decreases as water temperature increases, further indicating its limited solubility. Lastly, the need for aquatic organisms to extract oxygen from the surrounding water or through specialized structures like gills highlights the challenge posed by oxygen's low solubility in water.
Why Mercury is used in manometer?
Mercury is used due to its higher specific gravity allowing the manometer physical size to be smaller in direct proportion to the weight of mercury vs weight of water.and its vapour pressure is negligible.these are the two reasons .
How chemistry is applied in Sport Industry?
Chemistry is applied in the sport industry in various ways, such as in the development of performance-enhancing drugs, analysis of blood and urine samples for doping tests, design of sports equipment with improved materials, and development of sports drinks and supplements to enhance athletic performance and recovery. Additionally, chemistry is crucial in understanding the physiological processes that occur during exercise and training to optimize athletes' performance and ensure their safety.
One example of a neat polymer is polyethylene. Neat polymers are pure forms of a polymer without any additives or fillers. This allows for studying the intrinsic properties and behavior of the polymer.
