Unit Processes MCQ Number 01500

Answer: a [Reason:] Sulfoxidation, this reaction is chemically quite similar to sulfochlorination, except that acetic anhydride is added.

Answer: a [Reason:] Aliphatic Compounds; Aldehydes and Epoxides. These compounds react easily with bisulfite to yield 1-hydroxy- and 2-hydroxyalkylsulfonates, respectively.

Answer: b [Reason:] Unsaturated Compounds. Alkenes in the presence of general reaction.

Answer: b [Reason:] water-soluble lignin sulfonates are produced annually as a by-product of the manufacture of paper pulp by heating wood under pressure with an aqueous solution of metallic bisulfite and sulphur dioxide.

Answer: a [Reason:] When SO₂ and SO₃ is compared, during usage of SO₂, it is the organic rather than the inorganic compound which undergoes the oxidation.

Answer: c [Reason:] When SO₂ is oxidised we get SO₃. The reaction is as follows: SO₂ + O —–> SO₃.

Answer: a [Reason:] Since SO₃ is made by the oxidation of SO₂, it can be said that, if SO₂ is taken as the starting point, two major steps are involved in sulfonating with a compound of 803 : (1) an oxidation step and (2) the sulfonation step proper.

Answer: d [Reason:] Use of SO₃-dioxane with the alkene (oxidation of both SO₂ and the organic compound before sulfonation), the reaction is as follows : CH₂=CH-C₆H₅ + SO₃( dioxane) ——–> HO₃SCH=CHC₆H₅.

Answer: b [Reason:] Sulfomethylation, here Sodium hydroxymethanesulfonates (“aldehyde bisulfite”) are used to sulfomethylate on reactive carbon atoms (e.g., in phenols or ketones) or on nitrogen (i.e., amines, amides, or sulfoamides).

Answer: b [Reason:] Sulfoethylation is an important industrial wetting agents are prepared by reacting long-chain fatty acid chlorides with salts of 2-hydroxyethanesulfonic acid, HOCH₂CH₂SO₃Na, or N-methyltaurine, CH₃NHCH₂CH₂SO₃Na.

Answer: d [Reason:] All of these compounds are used as a Sulfonating agent in industries.

Answer: c [Reason:] Sulfonating may be defined as any chemical process by which the sulfonic acid group -S0₂0H, or the corresponding salt or sulfonyl halide group (e.g., -S0₂Cl), is introduced into an organic compound.

Answer: b [Reason:] Introduction of -SO2Cl is known as Sulfochlorination, which is used for Sulfonation.

Answer: d [Reason:] For Sulfonation, numerous methods are used such as: sulfochlorination

Answer: a [Reason:] Sulfation involves placement of the -OS0₂0H group on carbon, yielding an acid sulphate (ROS0₂0H), or of the -S0₄– group between two carbons, forming the sulphate ROS0₂0R.

Answer: a [Reason:] Sulfated alkyl group into an organic compound. It is convenient to classify sulfonates into four main chemical types: (1) aliphatic and alicyclic, (2) aromatic, (3) heterocyclic, and (4) N-sulfonates or sulfamates. The first three types have the -S020H group on carbon

Answer: b [Reason:] Condensation procedures refer to the reaction of organic sulfonate “building blocks” (such as HOCH2CH2S03Na) with other organic compounds (such as long-chain acid chlorides) to form new sulfonates with altered properties, these methods include sulfoalkylation

Answer: a [Reason:] Sulfonating and sulphating agents are of two types-inorganic and organic. The latter type is employed in the condensation procedures.

Answer: d [Reason:] The major quantity of sulfonates and sulfates is both marketed and used in salt form, the category includes detergents, emulsifying, de emulsifying, penetrating, wetting and solubilizing agents, lubricant additives, and rust inhibitors.

Answer: b [Reason:] Polymeric sulfonates include dispersing agents, elastomers, water-soluble synthetic gums and thickening agents, and ion-exchange resins which function as strong acids with complete water insolubility, an unusual combination of properties leading to many important applications.

Answer: c [Reason:] Aromatic sulfonyl chlorides-RS0₂Cl-are useful for preparing sulfonamides (including sulpha drugs, dyes, tanning agents, plasticizers, and the sweetening agent saccharin) and sulfonate esters (insecticides).

Answer: b [Reason:] The slurry system, has two reactors one used for the Oxo step and the other for hydrogenation steps.

Answer: b [Reason:] An alternative method of hydrogenation uses a copper chromite catalyst. In this case, metallic cobalt is removed from the crude product before hydrogenation.

Answer: c [Reason:] The Oxo process has provided a new source of high boiling aliphatic alcohols.

Answer: c [Reason:] Derivatives of isooctyl alcohol such as isooctanoic acid and isooctylamine are used in manufacturing paint driers and as surface-active agents.

Answer: b [Reason:] The high-molecular-weight alcohols are used as intermediates for preparing surface-active agents and plasticizers.

Answer: a [Reason:] The isosynthesis are designed to produce high yields of oxygenated materials. The isosynthesis yields highly branched aliphatic hydrocarbons and aromatics.

Answer: b [Reason:] The isosynthesis yields both highly branched aliphatic hydrocarbons and aromatics.

Answer: c [Reason:] The complexity of separating the mixtures of oxygenates and paraffinic and olefinic hydrocarbons. Fractionation alone may not be sufficient, because of overlapping boiling points and formation of azeotropes between oxygenates and hydrocarbons.

Answer: c [Reason:] The SynoI process utilizes a high ratio of gas recycle, and because the products are carried out of the reactor rapidly, the high-molecular-weight alcohols are not dehydrated.

Answer: b [Reason:] The products from the synthesis over iron nitride are predominantly of low molecular weight.

Answer: c [Reason:] Most of the world’s ammonia supply is manufactured by the addition of hydrogen to nitrogen over an iron-based catalyst at elevated temperatures and pressures.

Answer: b [Reason:] The reaction of ‘nitrogen with hydrogen to form ammonia is a highly exothermic reaction. According to Le Chatelier.

Answer: b [Reason:] The amount of ammonia formed at equilibrium decreases as the temperature is increased and increases as the pressure is increased, in accordance with the Le Chatelier Braun principle.

Answer: c [Reason:] To obtain maximum conversion percentages at the selected operating pressures and temperatures, the law of mass action dictates that nitrogen and hydrogen be kept at the stoichiometric ratio of 1:3 and that gases which would cause lower partial pressures of the reactants should not be present.

Answer: a [Reason:] Highly purified synthesis gas is a prime requirement for synthetic ammonia manufacture, and since its nitrogen content originates from air, hydrogen is the more costly component.

Answer: a [Reason:] Natural gas is the major source of hydrogen, the reaction is as follows: CH₄ + H₂O —-> CO + 2H₂O.

Answer: c [Reason:] The synthesis of HCN from ammonia, methane (natural gas), and air. The over-all reaction CH₄ + NH₃ + 1.5 O₂—–>HCN + 3H₂0 can be carried out effectively at about 1000°C over platinum-alloy screen catalysts.

Answer: b [Reason:] In order to obtain optimum yields, it is necessary to use less oxygen (as air) than the amount shown in the above equation, to prevent excessive oxidation of ammonia to nitrogen oxides and methane to carbon oxides.

Answer: a [Reason:] C6H5-Cl + NH₃—–> C₆H₅-NH₂ + HCl.

Answer: d [Reason:] An increase in the NH3 ratio results in: (1) a better yield of aniline, (2) an increase in the ratio of aniline to phenol, and (3) a slight diminution in the yield of diphenylamine.

Answer: c [Reason:] The compound name is methylaniline, as methyl group -CH₃ is attached to the amine group.

Answer: b [Reason:] In fatty acids, since oil or liquefied fat is insoluble in water, two liquid phases exist during hydrolysis, and the reaction rate, of course, depends upon their surface of contact–the greater the surface, the faster the saponification.

Answer: d [Reason:] The chief carbohydrates are the sugars, cellulose, and starch with its related polysaccharides.

Answer: b [Reason:] The chief carbohydrates are the sugars, cellulose, and starch with its related polysaccharides. Of these, the only ones hydrolysed in large-scale industrial operations are the pentoses, from which furfural is obtained, and starch, from which glucose is produced.

Answer: d [Reason:] The cost of raw material is the sum of six items: (1) cost at point of production, (2) cost of collection, (3) cost of transportation, (4) cost of storage to ensure year-round supply, (5) cost of preparation for use, (6) and cost of disposing of by-products.

Answer: c [Reason:] In hydrolysis of Starch to Sirup and Dextrose, in presence of water the catalytic effect of acids is to cleave these glucosidic linkages and at the same time introduce the elements of water at the point of cleavage.

Answer: c [Reason:] In hydrolysis of Starch to Sirup and Dextrose, the reaction is accelerated by increased temperature and by increased acid concentration (lower pH).

Answer: b [Reason:] Such so-called “crude” sugars are not generally used directly for edible purposes but find utility as fermentation substrates, as a base for the manufacture of caramel colour, in the finishing of leather, and in the manufacture of viscose rayon.

Answer: b [Reason:] A commercial continuous converter installation for dextrose manufacture employing a continuous, automatically controlled step for the hydrolysis of starch.

Answer: c [Reason:] The most important advantages of continuous hydrolysis are the ability to maintain a high production rate and the uniform control of quality.

Answer: a [Reason:] Dextrose equivalent, by varying acid concentration, holding time, or temperature within the system, the D.E. produced in the hydrolysed product can be varied over a wide range. At very low D.E., the product has a paste like consistency because of the high percentage of incompletely hydrolysed starch. As the D.E. level is raised, the product becomes more fluid and less pasty, the viscosity decreasing as D.E. increases.