Subject Materials for Chemistry
... broken glasses are add to the raw materials and then heated to 14000C (1673K) in the furnace. Cullet lowers the melting point of the batch. The following chemical reactions takes place to form molten glass, over molten glass scum is formed. The scum is skimmed off. ...
... broken glasses are add to the raw materials and then heated to 14000C (1673K) in the furnace. Cullet lowers the melting point of the batch. The following chemical reactions takes place to form molten glass, over molten glass scum is formed. The scum is skimmed off. ...
chem - CBSE Guess
... Rancidity: The oily and fatty food oxidizes and give bad smell and test is called rancidity.Preventatioin:By adding antioxidant which slow down the process of oxidation.2. Vaccum packing,3Flusing N2 gas in chips packets.3.Refrigeration. Q.Explain the various types of reactions with one example of ea ...
... Rancidity: The oily and fatty food oxidizes and give bad smell and test is called rancidity.Preventatioin:By adding antioxidant which slow down the process of oxidation.2. Vaccum packing,3Flusing N2 gas in chips packets.3.Refrigeration. Q.Explain the various types of reactions with one example of ea ...
664
... Any nitric oxide produced in small amounts may be removed by passage through FeSO4 solution. Alternatively, the gas may be obtained by warming a solution of ammonium nitrate in nitric acid containing a small amount of hydrochloric acid. Pure nitrous oxide may be prepared by treating a solution of so ...
... Any nitric oxide produced in small amounts may be removed by passage through FeSO4 solution. Alternatively, the gas may be obtained by warming a solution of ammonium nitrate in nitric acid containing a small amount of hydrochloric acid. Pure nitrous oxide may be prepared by treating a solution of so ...
Atomic Polar Tensor Transferabllity and Atomic Charges kr the
... In a recent work,’ a method for partitioning the dipole moment vector and the atomic polar tensor has been proposed. In the present work, that method is applied to the fluoromethanes CF,H, with x = 1-4. By the transference of the experimental polar tensors to different but related molecules, the inf ...
... In a recent work,’ a method for partitioning the dipole moment vector and the atomic polar tensor has been proposed. In the present work, that method is applied to the fluoromethanes CF,H, with x = 1-4. By the transference of the experimental polar tensors to different but related molecules, the inf ...
Compounds of Chlorine
... Hydrogen chloride (HCl) is prepared by the reaction of concentrated sulfuric acid (H2 SO4 ) with either NaCl or concentrated HCl solution. Hydrogen chloride is a polar molecule with a dipole of 1.08 D. However, the lower polarity as compared to that of hydrogen uoride (1.91 D) is consistent with th ...
... Hydrogen chloride (HCl) is prepared by the reaction of concentrated sulfuric acid (H2 SO4 ) with either NaCl or concentrated HCl solution. Hydrogen chloride is a polar molecule with a dipole of 1.08 D. However, the lower polarity as compared to that of hydrogen uoride (1.91 D) is consistent with th ...
KISS Notes
... From the Medieval to the Modern After the collapse of the Roman Empire the various cultures that dominated the “Dark Ages” still had ironbased technologies. The next great technological change was the “Industrial Revolution” which began about 1750 in England. This had many aspects, but the big chang ...
... From the Medieval to the Modern After the collapse of the Roman Empire the various cultures that dominated the “Dark Ages” still had ironbased technologies. The next great technological change was the “Industrial Revolution” which began about 1750 in England. This had many aspects, but the big chang ...
Oxidation Numbers
... oxidation number has decreased In a redox reaction, the RA is always oxidized. the RA is the reactant whose oxidation number has increased ...
... oxidation number has decreased In a redox reaction, the RA is always oxidized. the RA is the reactant whose oxidation number has increased ...
Downloaded on 2017-02
... The operation of nanoscale devices can depend on the chemical identity or morphology of a single layer of atoms in a 2D material or at an interface. 1–3 Preparing material interfaces with such atomic-scale control is a substantial challenge. One step towards this goal would be understanding the reac ...
... The operation of nanoscale devices can depend on the chemical identity or morphology of a single layer of atoms in a 2D material or at an interface. 1–3 Preparing material interfaces with such atomic-scale control is a substantial challenge. One step towards this goal would be understanding the reac ...
Growth mechanism of amorphous hydrogenated carbon
... it was observed that the a-C:H growth rate in a lowtemperature plasma decreases with increasing substrate temperature. This general behavior is caused by a balance between a temperature-independent incorporation of hydrocarbon radicals during film deposition and a temperature-dependent re-etching of ...
... it was observed that the a-C:H growth rate in a lowtemperature plasma decreases with increasing substrate temperature. This general behavior is caused by a balance between a temperature-independent incorporation of hydrocarbon radicals during film deposition and a temperature-dependent re-etching of ...
2. CHEMICAL ACTIVITY of the METALS 3. PATTERNS of the
... dissolves into the liquid. This is explosion because it forms a soluble ionic compound. Exactly what the compound is, depends on which acid is used. ...
... dissolves into the liquid. This is explosion because it forms a soluble ionic compound. Exactly what the compound is, depends on which acid is used. ...
Descriptive Chemistry of Elements p
... Aluminium is the third most abundant element in the earth’s crust. Aluminosilicates are found in clay, kaolin, mica and feldspar. The more important aluminium ore is Bauxide from which aluminium is extracted on a large scale. Bauxide (Al2O3) contains more silica and iron oxides as impurities. Al2O3 ...
... Aluminium is the third most abundant element in the earth’s crust. Aluminosilicates are found in clay, kaolin, mica and feldspar. The more important aluminium ore is Bauxide from which aluminium is extracted on a large scale. Bauxide (Al2O3) contains more silica and iron oxides as impurities. Al2O3 ...
s-BLOCK ELEMENTS - einstein classes
... alkali metal ions in decreasing order is Li+ > Na+ > K+ > Rb+ > Cs+. Potassium is lighter than sodium. The alkali metals do not occur free in nature. This is because they have very low ionization enthalpy and form electropositive ions. Sodium is less reactive than potassium this is because the ioniz ...
... alkali metal ions in decreasing order is Li+ > Na+ > K+ > Rb+ > Cs+. Potassium is lighter than sodium. The alkali metals do not occur free in nature. This is because they have very low ionization enthalpy and form electropositive ions. Sodium is less reactive than potassium this is because the ioniz ...
Slide 1
... • Leaching reactions not perfectly selective other elements in solution as well, not just Cu. These need to be removed. • After leaching, Cu in solution can be very dilute. need a way to concentrate it. • Both of these are generally done using ion exchange processes, the two most common being io ...
... • Leaching reactions not perfectly selective other elements in solution as well, not just Cu. These need to be removed. • After leaching, Cu in solution can be very dilute. need a way to concentrate it. • Both of these are generally done using ion exchange processes, the two most common being io ...
General - Department of Mechanical Engineering
... The chemical environment to which a material is subjected in its life span may cause changes in the material properties. Corrosion is the reaction of the engineering material with its environment with a consequent deterioration in properties of the material. Corrosion will include the reaction of ...
... The chemical environment to which a material is subjected in its life span may cause changes in the material properties. Corrosion is the reaction of the engineering material with its environment with a consequent deterioration in properties of the material. Corrosion will include the reaction of ...
Chemistry of METALS
... (b) In the Downs process, (used for manufacture of sodium), a certain salt is added to lower the melting point of sodium chloride from about 8000C to about 6000C. (i) Name the salt that is added (1mk) Calcium chloride (ii) State why it is necessary to lower the temperature(1mk) To reduce the cost of ...
... (b) In the Downs process, (used for manufacture of sodium), a certain salt is added to lower the melting point of sodium chloride from about 8000C to about 6000C. (i) Name the salt that is added (1mk) Calcium chloride (ii) State why it is necessary to lower the temperature(1mk) To reduce the cost of ...
s - Wits Structural Chemistry
... • Leaching reactions not perfectly selective other elements in solution as well, not just Cu. These need to be removed. • After leaching, Cu in solution can be very dilute. need a way to concentrate it. • Both of these are generally done using ion exchange processes, the two most common being io ...
... • Leaching reactions not perfectly selective other elements in solution as well, not just Cu. These need to be removed. • After leaching, Cu in solution can be very dilute. need a way to concentrate it. • Both of these are generally done using ion exchange processes, the two most common being io ...
GROUP 13 ELEMENTS -THE BORON FAMILY -
... Bauxite is high above 2000°C. This mean that large amount of energy is needed. To minimize the energy operational cost, some cryolite (Na3AlF6 ) reduces the melting point to about 1000°C. The aluminium metal is produced at the cathode and oxygen is liberated at the anode where it reacts with carbon ...
... Bauxite is high above 2000°C. This mean that large amount of energy is needed. To minimize the energy operational cost, some cryolite (Na3AlF6 ) reduces the melting point to about 1000°C. The aluminium metal is produced at the cathode and oxygen is liberated at the anode where it reacts with carbon ...
WIPO IPC: Internet Publication
... macromolecular compounds, and their methods of preparation; o applied chemistry, which covers compositions containing the above compounds, such as: glass, ceramics, fertilisers, plastics compositions, paints, products of the petroleum industry. It also covers certain compositions on account of their ...
... macromolecular compounds, and their methods of preparation; o applied chemistry, which covers compositions containing the above compounds, such as: glass, ceramics, fertilisers, plastics compositions, paints, products of the petroleum industry. It also covers certain compositions on account of their ...
Similarities in the electrical properties of transition metal–hydrogen
... carrier emission. In contrast, defects with donor states in the upper half of the band gap as well as defects with acceptor states in the lower half of the band gap remain charged after carrier emission and the Coulombic attraction between them and the emitted carriers leads to an enhancement in the ...
... carrier emission. In contrast, defects with donor states in the upper half of the band gap as well as defects with acceptor states in the lower half of the band gap remain charged after carrier emission and the Coulombic attraction between them and the emitted carriers leads to an enhancement in the ...
06_chapter 1
... industry to coat tools, and hence, one of the best-known and investigated ones is ...
... industry to coat tools, and hence, one of the best-known and investigated ones is ...
Sample chapter Iron Oxides
... hematite by solid‐phase dehydration is unlikely because the temperature needed is usually too low. Nor has “rehydration” of hematite to goethite been observed. Admittedly, the coexistence of ferrihydrite and hematite in soils has not been found so far. Besides the global distribution, regular variat ...
... hematite by solid‐phase dehydration is unlikely because the temperature needed is usually too low. Nor has “rehydration” of hematite to goethite been observed. Admittedly, the coexistence of ferrihydrite and hematite in soils has not been found so far. Besides the global distribution, regular variat ...
PPT - Foamtec
... Mopping is a mechanical action on the surface This loosens particulate and residues which removes some of the contaminates While loosening and removing some, it does not remove all Surface wetting is minimal and less than two minutes of contact time is typical ...
... Mopping is a mechanical action on the surface This loosens particulate and residues which removes some of the contaminates While loosening and removing some, it does not remove all Surface wetting is minimal and less than two minutes of contact time is typical ...
Review - Sociedade Brasileira de Química
... introduced in the system so that the cell can work without being limited by exhaustion of the reactants as it happens with other batteries. As mentioned above, other fuels such as ethanol or hydrocarbons are thinkable as candidate substances for the anode reaction. However, at present, the H2/O2 FC ...
... introduced in the system so that the cell can work without being limited by exhaustion of the reactants as it happens with other batteries. As mentioned above, other fuels such as ethanol or hydrocarbons are thinkable as candidate substances for the anode reaction. However, at present, the H2/O2 FC ...
CORROSION: origin and prevention (1)
... corrosion is that through deterioration of the borders the mutual connection of the crystals gets lost whereby the grains in the end lie loose. There are three main reasons through which the borders become sensitive to corrosion. First of all through precipitation of alloy elements which at a certai ...
... corrosion is that through deterioration of the borders the mutual connection of the crystals gets lost whereby the grains in the end lie loose. There are three main reasons through which the borders become sensitive to corrosion. First of all through precipitation of alloy elements which at a certai ...
Flux (metallurgy)
In metallurgy, a flux (derived from Latin fluxus meaning “flow”) is a chemical cleaning agent, flowing agent, or purifying agent. Fluxes may have more than one function at a time. They are used in both extractive metallurgy and metal joining.Some of the earliest known fluxes were carbonate of soda, potash, charcoal, coke, borax, lime, lead sulfide and certain minerals containing phosphorus. Iron ore was also used as a flux in the smelting of copper. These agents served various functions, the simplest being a reducing agent which prevented oxides from forming on the surface of the molten metal, while others absorbed impurities into the slag which could be scraped off the molten metal.As cleaning agents, fluxes facilitate soldering, brazing, and welding by removing oxidation from the metals to be joined. Common fluxes are: ammonium chloride or rosin for soldering tin; hydrochloric acid and zinc chloride for soldering galvanized iron (and other zinc surfaces); and borax for brazing or braze-welding ferrous metals. In the process of smelting, inorganic chlorides, fluorides (see fluorite), limestone and other materials are designated as ""fluxes"" when added to the contents of a smelting furnace or a cupola for the purpose of purging the metal of chemical impurities such as phosphorus, and of rendering slag more liquid at the smelting temperature. The slag is a liquid mixture of ash, flux, and other impurities. This reduction of slag viscosity with temperature, increasing the flow of slag in smelting, is the original origin of the word flux in metallurgy. Fluxes are also used in foundries for removing impurities from molten nonferrous metals such as aluminum, or for adding desirable trace elements such as titanium.In high-temperature metal joining processes (welding, brazing and soldering), the primary purpose of flux is to prevent oxidation of the base and filler materials. Tin-lead solder (e.g.) attaches very well to copper, but poorly to the various oxides of copper, which form quickly at soldering temperatures. Flux is a substance which is nearly inert at room temperature, but which becomes strongly reducing at elevated temperatures, preventing the formation of metal oxides. Additionally, flux allows solder to flow easily on the working piece rather than forming beads as it would otherwise.The role of a flux in joining processes is typically dual: dissolving of the oxides on the metal surface, which facilitates wetting by molten metal, and acting as an oxygen barrier by coating the hot surface, preventing its oxidation. In some applications molten flux also serves as a heat transfer medium, facilitating heating of the joint by the soldering tool or molten solder.Fluxes for soft soldering are typically of organic nature, though inorganic fluxes, usually based on halogenides and/or acids, are also used in non-electronics applications. Fluxes for brazing operate at significantly higher temperatures and are therefore mostly inorganic; the organic compounds tend to be of supplementary nature.