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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
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.
What is the effect of humidification on wet bulb temperature?
Humidification increases the moisture content in the air, which can lower the wet bulb temperature by increasing the rate of evaporation. This can lead to a more comfortable indoor environment by reducing the apparent temperature felt by individuals.
Yes, ozone can degrade epoxies by breaking down their chemical bonds, leading to a loss of strength and durability in the material. It is important to protect epoxy materials from ozone exposure to ensure their long-term performance.
What does a monomer and a ploymer make?
A monomer is a small molecule that can bond with other monomers to form a polymer through a process called polymerization. Polymers are large molecules made up of repeating units of monomers, which combine to form long chains or networks.
What are the non metalic coatings?
Non metallic coating is not very stable except Graphite coating other coating includes Sulphur coating and organic coating of polymers the temporary coating of wax ,grease and oils also may be used.
What is cement grade limestone?
See
http://books.google.com/books?id=06s_8PnQIEcC&pg=PA18&lpg=PA18&dq=Cement+grade+limestone&source=bl&ots=E62c6KD0EV&sig=oxl0dtW_IwEidZw29ODE7f9K-tA&hl=en&ei=cI3gSoexIo2ssgPd-fHlCA&sa=X&oi=book_result&ct=result&resnum=10&ved=0CCIQ6AEwCTgK#
Why Hot briquetted iron have low carbon?
Hot briquetted iron (HBI) has low carbon content because the iron ore is processed in a direct reduction process that reduces the oxygen in the ore. This process results in iron that has a significantly lower carbon content compared to traditional blast furnace iron.
This is just a guess, but if I saw that in an archaic formulary I'd probably assume they were talking about aqueous sodium hydroxide. "Liquor" is sometimes used in chemistry as a general term meaning solution, and "caustic soda" is an old term for sodium hydroxide.
Secondary air will hepl to reduce incinerator temp?
Secondary air can help reduce incinerator temperature by providing additional oxygen for more complete combustion of the waste materials. This can help optimize the incineration process and minimize the production of unburned pollutants that can contribute to higher temperatures. Proper control and adjustment of secondary air levels can improve combustion efficiency and reduce overall incinerator temperature.
What texture represents a single long period of cooling and crystallization?
A coarse-grained texture typically represents a single long period of cooling and crystallization. This texture forms when the magma has had enough time to cool slowly and crystals have had time to grow to a visible size.
Intercontinental Ballistic Missiles (ICBMs) can travel distances of up to 10,000 kilometers or more depending on the specific missile design. These missiles are capable of reaching targets on the other side of the world, making them a key component of long-range strategic weapons systems.
What is the role of microorganisms in decomposition?
Think how high all the detritus would be if something did not decompose it, especially all that cellulose plant make and die with. We are talking trillions of tons of indigestible fiber made per year. Some bacteria can digest this fiber; fortunately.
Yes, It is. The name "potassium" comes from the word "potash", as potassium was first isolated from potash. Potassium is a soft silvery-white metallic alkali metal that occurs naturally bound to other elements in seawater and many minerals.
its pretty much over once a car gets to that stage, even if you give it a 3000 dollar body job , the rust will return. Best advice is buy a newer car and underspray it every summer. Corrosion is like cancer - you need to remove it and protect non-damaged areas against it with undercoatings. Corrosion in a battery compartment can be dramatically reduced by saturating the area with baking soda dissolved in warm water.
What is the Definition of recoverable grade of ore?
The true mill-head grade of an ore-stream in percent, ounces, or parts per million of a metal or mineral, less extractive metallurgical losses; the proportion of an ore material actually recovered.
Applications of nitrile rubber?
Nitrile rubber is also referred to as also Nitrile butadiene rubber, or "NBR". The products are used in several industries because the general properties of NBR are not altered by minor structural/compositional differences.
The major uses for Nitrile rubber are in the healthcare industry and the automobile industry because the gloves are resistant to many solvents.
The nitrile gloves gloves are resistant to oil, fuel, and other chemicals.
In the healthcare industry, Nitrile gloves are used as an alternative to Latex gloves because some people experience allergic reactions to Latex gloves.
The gloves can be viewed at the following link:
http://www.twinmeddirect.com/gloves_nitrile.html">nitrile
