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Which of the following is not an oxo-acid of nitrogen?
Hyponitric acid does not exist. The rest three mentioned are commonly occurring oxoacids of nitrogen. Hyponitrous acid, H2N2O2 is an isomer tautomer of nitramide, with the structure of the former being HON = NOH. Nitrous acid, HNO2 is usually formed in the atmosphere prior conversion to nitric acid. It is highly unstable.
Which of the following reactions best represents lab scale preparation of nitric acid?
The most appropriate lab scale preparation method of nitric acid, HNO3 is using an alkali nitrate salt and react it with concentration nitric acid in a glass retort. Nitrous acid being highly unstable decomposes into nitric acid. The other two sets of reaction represent the industrial process of manufacturing nitric acid i.e. Ostwald’s process.
What is the catalyst used in the industrial manufacture of nitric acid?
Pt-Rh gauze sheet is widely used as the catalyst in ammonic oxidation, the first step of Ostwald’s process. Fe2O3 is used in Haber’s process; V2O5 in contact process and Zn (Hg) is used in Clemmensen reduction of aldehydes.
Which of these gases is released upon treating zinc with diluted and then concentrated nitric acid?
The products released depend on the concentration of nitric acid. In case of zinc metal, diluted nitric acid treatment release nitrous oxide and concentrated nitric acid causes the release of nitrogen dioxide.
Which reagent is predominantly used in pickling of stainless steel?
Pickling of stainless steel is the process of removal of a thin layer of the alloyed metal from the surface. The common reagent used is nitric acid along with calculated amounts of hydrofluoric acid.
How many moles of nitric acid is required to convert 1 mole of sulfur to sulfuric acid?
1 mole of sulfur, S8 requires 48 moles of concentrated nitric acid. The reaction is given by S8 + 48HNO3 → 8H2SO4 + 48NO2 + 16H2O. 10, 4 and 20 moles of concentrated nitric acid is required to produce iodic acid, carbon dioxide and phosphoric acid from 1 mole of iodine, carbon and phosphorus, respectively.
What product(s) is/are formed when aluminum metal is treated with concentrated nitric acid?
Aluminum does not dissolve in nitric acid. This is because treatment with nitric acid results in the formation of a tough oxide layer. This oxide layer prevents it from further reacting with the oxide. Hence, the compound formed is Al2O3 i.e. aluminum (III) oxide.
What is the nitric acid – water composition by mass, respectively, for the components to form an azeotrope?
Experimentally, it is determined that nitric acid and water form a constant boiling azeotrope at 68% – 32% by mass composition, respectively. Here, it becomes impossible to separate water and nitric acid by distillation methods. Thus, concentrated sulfuric acid is used for dehydration and removal of water.
What is the name of the industrial process to manufacture nitric acid?
Ostwald’s process is the name of the industrial process to manufacture nitric acid in bulk. It involves the oxidation of ammonia which forms nitric oxide. This is then reacted with more oxygen to produce nitrogen dioxide. Subsequently, nitrogen dioxide is dissolved in water to produce adequate concentrations of nitric acid. Contact process is used to produce sulfuric acid. Solvay is used to obtain sodium carbonate and Haber-Bosch to obtain ammonia.
Which of the following is true regarding nitric acid?
Nitric acid is a very weak reducing agent since it has a polar O – H bond. This breaks to donate the H+ ion which is why it is a strong oxidizing agent and a strong acid. Since there is only one cleavable O – H bond, the basicity of nitric acid is unity (one HNO3 molecule can donate only 1 H+ ion). It exists as a planar molecule in vapor phase.
What happens to the size of atoms of elements of p-block as we move from left to right in the same period?
The size of the atoms of the elements decrease from left to right in the same period. Considering the row to be the same, the electrons are added to the same shell. However, the increase in atomic number reflects the increase in number of protons i.e. the positive charge. Hence, the overall effective nuclear charge increases. Consequently, the electron cloud is pulled even more closer to the nucleus of the atom. Therefore, the size decreases.
Why does nitrogen show poor tendency towards catenation?
The N – N single bond is highly weak and unstable due to high magnitude of inter-electronic repulsions of non-bonding electrons which in turn is caused by the single bond’s small bond length. As a result the catenation tendency becomes weaker due to the mentioned factors leading to instability.
Which gas is released when copper chips are subjected to concentrated nitric acid?
Treating copper chips with concentrated nitric acid releases toxic brown gas, NO2, nitrogen (IV) oxide. It is a reddish-brown gas with pungent odor.
Which of the following ions is the brown ring test useful for determining?
The brown ring test is used to determine the presence of nitrate ions, NO3-. Dilute ferrous sulfate solution is added to solution containing nitrate ion. Following this, concentrated sulfuric acid is added along the sides of the test tube. A brown ring is formed at the junction concentrated sulfuric acid and solutions.
What is the oxidation state of nitrogen in di-nitrogen trioxide?
Di-nitrogen trioxide is formulated as N2O3
The oxidation state of oxygen atom is fixed at -2 since it is the more electronegative atom in this case.
If oxidation state of nitrogen is assumed to be ‘x’, then:
2x + (3x -2) = 0
2x – 6 = 0
x = +3
The oxidation state of nitrogen is +3.
What catalyst is used for oxidation of ammonia to produce nitric acid?
Ammonia is oxidized to nitrogen (II) oxide in the presence of Pt/Rh gauze catalyst at a temperature of 500 K and a pressure of 9 bars. The nitrous oxide is then converted to nitrogen dioxide which is further reacted with water to produce nitric acid. The NO formed is recycled.
What shape is the HNO3 molecule in its gaseous state?
In the gas state, the nitric acid molecule has a triangular planar shape with a steric number of 3 no lone pairs of electron. There are two major resonance forms of nitric acid.
What is the primary product of Haber-Bosch process?
The primary product of Haber-Bosch process is ammonia, NH3. In this process, N2(g) and H2(g) are reacted at a high temperature of 700 K and 200 atm pressure in presence of iron-bed catalysts. It is an exothermic process which takes place in accordance with Le Chatelier’s principle. Nitric acid is produced by Ostwald’s process. Nitrous acid is produced by reacting sodium nitrite with a mineral and pyridine by Chichibabin process.
What is the maximum covalency of the nitrogen atom?
Covalency of an atom refers to the number of electrons that atom can share to form chemical bonds. Usually it is the number of bonds formed by the atom. In case of nitrogen, its atom can share up to four electrons, one in the s-subshell and the other three in the p-subshell. In addition to this, absence of d-orbitals restricts its covalency to four only.
What is the type of metallurgy in which the ore is leached and the metal is collected by using electrolysis?
Hydrometallurgy is a technique within the field of extractive metallurgy, the obtaining of metals from their ores. Hydrometallurgy involves the use of aqueous solutions for the recovery of metals from ores, concentrates, and recycled or residual materials.
When is the ore subjected to leach?
The ore is subjected to leaching when both the ore and impurity are insoluble in water. Leaching process is commonly referred to as extraction. This is a process in which water soluble substances are washed out from soil or wastes.
Roasting results in the formation of oxides. But why are oxide ores are subjected to roasting?
Oxide ores are subjected to roasting to remove the volatile impurities in the form of their oxides. It is easier to obtain metals from their oxides (by reduction) than from carbonates or sulphides. So before reduction can be done, the ore is converted into metal oxide.
How is ore-dressing of iron done?
In magnetic separators, the effect of magnetism is used to separate ferromagnetic materials from non-magnetic materials. In principle, this process is also suitable for the iron ores siderite and hematite, which become weakly magnetic when heated.
Which of the following metals is not extracted by electrolysis?
Actually the extraction of a metal from its ore depends upon the selection of a proper reducing agent. Iron is a moderately active metal and its oxides can be reduced using carbon and not by using electrolysis. Reactive metals, such as aluminium, are extracted by electrolysis, while a less reactive metal, such as iron, may be extracted by reduction with carbon.
What is the main reaction occurring in the blast furnace during extraction of iron from haematite?
The main reaction occurring in the blast furnace during extraction of iron from haematite is:
Fe2O3 + 3CO → 2Fe + 3CO2
This reaction involves the reduction of iron (III) oxide to iron and oxidation of carbon monoxide to carbon dioxide.
Which of the following ores are concentrated by froth flotation?
The froth flotation method is widely used for the concentration of sulphide ores such as zinc blende (ZnS), copper pyrites (CuFeS2), galena (PbS), etc. This method is based upon the fact that the surface of the sulphide ores is preferentially wetted by oils while that of gangue is preferentially wetted by water.
Which of the following statements is wrong?
Smelting is the process of extraction of a metal from its oxide by reduction with carbon (coke). Alkali metals, alkaline earth metals, etc. cannot be prepared by reduction of their respective oxides with carbon. The slag formed during smelting has high melting point and is lighter than the metal.
Which of the following is the chief ore of aluminium?
Bauxite is the chief ore of aluminium. The composition of bauxite is Al2O3.2H2O, it’s a mixture of hydrated iron oxide and hydrated aluminium oxide. Kaolinite is another ore of aluminium but its less availability is less compare to bauxite and the extraction of aluminium from kaolinite is a hard process and costs more.
What is the composition of Kaolinite?
Kaolinite is a soft clay type material with the chemical composition [Al2(OH)4Si2O4]. It’s basically made up of hydrous aluminium silicates, they comprise the principle ingredients of kaolin (china clay). It is usually white in appearance and sometimes red due to iron oxide.
Which of the following is not a suitable ore for extracting iron?
The composition of iron pyrite is FeS2. Iron pyrite is exothermic and can cause hazard in mines, it is more economical to extract iron from other ores such as magnetite and hematite. Pyrites are generally unstable and might turn into sulfurous minerals.
What is the concentration of zinc in calamine?
The chemical composition of calamine is ZnCO3 with 98 percent concentration of zinc. It is available in abundance and can be artificially prepared in laboratories. It is used in medication to relieve pain and itching.
Silver is extracted from which of the following ore?
rgentite also knows as silver glance is the only given silver ore in the above options with chemical composition Ag2S. Silver is extracted from silver glance by a simple process known as smelting or chemical leaching.
What is the composition of brass?
Brass is an alloy of copper and zinc, typically 63 percent copper and 37 percent zinc. Sometimes poor quality brass may contain a little lead. Brass is naturally corrosion resistant and has very low friction. It is used for construction of water pipes and fittings.
Which of the following is the finest iron ore?
Magnetite is the finest iron ore with a very high content of iron up to 72 percent. It has a very good magnetic property and is valuable in electrical industry. Hematite is another very important iron ore but the iron content of hematite is slightly lower than magnetite.
Which of the following is not an example of a water-in-oil emulsion?
In an emulsion of water-in-oil (w/o), water is the dispersed phase and oil is the dispersion medium. Cod liver oil, butter and cold cream are all examples of the water-in-oil type of emulsions.
What is the difference between vanishing cream and cold cream?
Vanishing cream is an oil-in-water emulsion, that is, oil is the dispersed phase and water is the dispersion medium. Cold cream is a water-in-oil emulsion, that is, water is the dispersed phase and oil is the dispersion medium.
Which of the following statements regarding emulsions is false?
Emulsions can be separated into their constituent liquids by boiling, freezing, centrifuging, electrostatic precipitation by adding large amounts of the electrolyte to precipitate out the dispersed phase or by chemical destruction of the emulsifying agent.
What is the emulsifier present in milk that makes it stable?
The emulsifier or emulsifying agent present in dairy emulsions is Casein. Casein is a slow-digesting dairy protein that people often take as a supplement.The most common form of casein is sodium caseinate.
What is the dispersion of a liquid in another liquid called?
The dispersion of a liquid in a solid is called gel. The dispersion of a gas in a liquid medium is called foam. The dispersion of a liquid in another liquid is called emulsion. The dispersion of a solid or liquid in a gaseous medium is called aerosol.
Which of the following statement about emulsions is true?
The digestion of fats in the intestines takes place by the process of emulsification. A small amount of the fat reacts with the alkaline solution present in the intestines to form a sodium soap.
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