Institute for Competitive Examinations
... A metal crystallizes with a face-centered cubic lattice. The edge of the unit cell is 408 pm. The diameter of the metal atom is : ...
... A metal crystallizes with a face-centered cubic lattice. The edge of the unit cell is 408 pm. The diameter of the metal atom is : ...
Preparation and reactions of some lower tungsten halides and
... fifty per cent sodium hydroxide and boiled to assure complete hydrolysis. The solution was cooled and diluted to 250 ml. in a volumetric flask. Aliquots were taken for the tungsten and halide analyses. For the tungsten analysis the solution was acidified with 6N nitric acid to a pH less than one and ...
... fifty per cent sodium hydroxide and boiled to assure complete hydrolysis. The solution was cooled and diluted to 250 ml. in a volumetric flask. Aliquots were taken for the tungsten and halide analyses. For the tungsten analysis the solution was acidified with 6N nitric acid to a pH less than one and ...
Laboratory Works and Home Tasks in General Chemistry
... Equivalence factor feq(X) is the number indicating which part of the real particle of substance X is equivalent to one hydrogen ion in the given acid-base reaction or to one electron in the oxidation-reduction reaction. This value is dimensionless and is calculated on the basis of stoichiometric co ...
... Equivalence factor feq(X) is the number indicating which part of the real particle of substance X is equivalent to one hydrogen ion in the given acid-base reaction or to one electron in the oxidation-reduction reaction. This value is dimensionless and is calculated on the basis of stoichiometric co ...
Question Bank (Class XI - Chemistry)
... Ans. Matter can neither be created nor destroyed in the course of a Physical or chemical process although it may change from one form to another. Q4. Which of the following statement about a compound is incorrect?(L2) (I) A molecule of a compound has atom of different elements. (II) A compound canno ...
... Ans. Matter can neither be created nor destroyed in the course of a Physical or chemical process although it may change from one form to another. Q4. Which of the following statement about a compound is incorrect?(L2) (I) A molecule of a compound has atom of different elements. (II) A compound canno ...
Fundamentals of Environmental Chemistry
... background in chemistry with the fundamentals of chemistry needed for a trade, profession, or curriculum of study that requires a basic knowledge of these topics. The second objective of the book is to provide a basic coverage of modern environmental chemistry. This is done within a framework of ind ...
... background in chemistry with the fundamentals of chemistry needed for a trade, profession, or curriculum of study that requires a basic knowledge of these topics. The second objective of the book is to provide a basic coverage of modern environmental chemistry. This is done within a framework of ind ...
chapter 20 - United International College
... electrodes (see Figure 19.1 of the text). If we physically separate the oxidizing agent from the reducing agent, the transfer of electrons can take place via an external conducting medium (a metal wire). ...
... electrodes (see Figure 19.1 of the text). If we physically separate the oxidizing agent from the reducing agent, the transfer of electrons can take place via an external conducting medium (a metal wire). ...
Chapter 15 Chemical Equilibrium
... concentrations are known, calculate the change in concentration that occurs as the system reaches equilibrium. 3. Use the stoichiometry of the reaction (that is, use the coefficients in the balanced chemical equation) to calculate the changes in concentration of all the other species in the equilibr ...
... concentrations are known, calculate the change in concentration that occurs as the system reaches equilibrium. 3. Use the stoichiometry of the reaction (that is, use the coefficients in the balanced chemical equation) to calculate the changes in concentration of all the other species in the equilibr ...
CHAPTER 9 Notes
... c. When 2.50 g of K and 1.00 g Cl2 react together, the mass of KCl produced is _____2.10 g_______________, the limiting reactant is____Cl2____________, and the reactant in excess is _______K__________________. ...
... c. When 2.50 g of K and 1.00 g Cl2 react together, the mass of KCl produced is _____2.10 g_______________, the limiting reactant is____Cl2____________, and the reactant in excess is _______K__________________. ...
Brief Contents - Educhimica.it
... 11. a. Since 10−6 defines the micro-prefix, 3.44 × 10−6can be written as 3.44 μs. b. 3,500 L can be written as 3.5 × 103 L. Since 103 defines the kilo-prefix, 3.5 × 103 L can be written as 3.5 kL. c. 0.045 m can be written as 4.5 × 10−2 m. Since 10−2 defines the centi-prefix, 4.5 × 10−2 m can be written a ...
... 11. a. Since 10−6 defines the micro-prefix, 3.44 × 10−6can be written as 3.44 μs. b. 3,500 L can be written as 3.5 × 103 L. Since 103 defines the kilo-prefix, 3.5 × 103 L can be written as 3.5 kL. c. 0.045 m can be written as 4.5 × 10−2 m. Since 10−2 defines the centi-prefix, 4.5 × 10−2 m can be written a ...
Low Temperature Precursors for SnOx Thin Films
... encouragement and useful discussions about the work presented within this thesis. I was fortunate to also have the wisdom and guidance of two other academic supervisors with Professor Kieran Molloy providing his wealth of knowledge and experience within the field of tin and materials chemistry and D ...
... encouragement and useful discussions about the work presented within this thesis. I was fortunate to also have the wisdom and guidance of two other academic supervisors with Professor Kieran Molloy providing his wealth of knowledge and experience within the field of tin and materials chemistry and D ...
- Chemistry
... The standard molar enthalpy of formation of liquid methanol, CH3OH(l), is the standard enthalpy change of the following reaction: ...
... The standard molar enthalpy of formation of liquid methanol, CH3OH(l), is the standard enthalpy change of the following reaction: ...
Solving Problems: A Chemistry Handbook
... they cannot be seen with an ordinary light microscope. The structure, composition, and behavior of all matter can be explained by atoms and the changes they undergo. Because there are so many types of matter, there are many areas of study in the field of chemistry. Chemistry is usually divided into ...
... they cannot be seen with an ordinary light microscope. The structure, composition, and behavior of all matter can be explained by atoms and the changes they undergo. Because there are so many types of matter, there are many areas of study in the field of chemistry. Chemistry is usually divided into ...
Descriptive Inorganic Chemistry
... escriptive inorganic chemistry was traditionally concerned with the properties of the elements and their compounds. Now, in the renaissance of the subject, with the synthesis of new and novel materials, the properties are being linked with explanations for the formulas and structures of compounds to ...
... escriptive inorganic chemistry was traditionally concerned with the properties of the elements and their compounds. Now, in the renaissance of the subject, with the synthesis of new and novel materials, the properties are being linked with explanations for the formulas and structures of compounds to ...
Solutions - ChemConnections
... Magnesium is an alkaline earth metal; Mg will oxidize to Mg2+. The oxidation state of hydrogen in HCl is +1. To be reduced, the oxidation state of H must decrease. The obvious choice for the hydrogen product is H2(g), where hydrogen has a zero oxidation state. The balanced reaction is Mg(s) + 2HCl(a ...
... Magnesium is an alkaline earth metal; Mg will oxidize to Mg2+. The oxidation state of hydrogen in HCl is +1. To be reduced, the oxidation state of H must decrease. The obvious choice for the hydrogen product is H2(g), where hydrogen has a zero oxidation state. The balanced reaction is Mg(s) + 2HCl(a ...
Chapter 4
... (a) is a strong electrolyte. The compound dissociates completely into ions in solution. (b) is a nonelectrolyte. The compound dissolves in water, but the molecules remain intact. (c) is a weak electrolyte. A small amount of the compound dissociates into ions in water. When NaCl dissolves in water it ...
... (a) is a strong electrolyte. The compound dissociates completely into ions in solution. (b) is a nonelectrolyte. The compound dissolves in water, but the molecules remain intact. (c) is a weak electrolyte. A small amount of the compound dissociates into ions in water. When NaCl dissolves in water it ...
CHAPTER 4 REACTIONS IN AQUEOUS SOLUTIONS
... and weak bases are weak electrolytes. They only ionize to a small extent in solution. Weak acids and weak bases are shown as molecules in ionic and net ionic equations. A net ionic equation shows only the species that actually take part in the reaction. ...
... and weak bases are weak electrolytes. They only ionize to a small extent in solution. Weak acids and weak bases are shown as molecules in ionic and net ionic equations. A net ionic equation shows only the species that actually take part in the reaction. ...
Solutions - ChemConnections
... Ka for HF is less than one, while the other hydrogen halide acids have Ka > 1. In terms of ∆GE, HF must have a positive ∆G orxn value, while the other HX acids have ∆G°rxn < 0. The reason for the sign change in the Ka value, between HF versus HCl, HBr, and HI is entropy. ∆S for the dissociation of H ...
... Ka for HF is less than one, while the other hydrogen halide acids have Ka > 1. In terms of ∆GE, HF must have a positive ∆G orxn value, while the other HX acids have ∆G°rxn < 0. The reason for the sign change in the Ka value, between HF versus HCl, HBr, and HI is entropy. ∆S for the dissociation of H ...
The role of aqueous-phase oxidation in the A
... mate change, air quality, and human health. Our ability to predict its formation and fate is hindered by uncertainties associated with one type in particular, organic aerosol (OA). Ambient OA measurements indicate that it can become highly oxidized in short timescales, but this is generally not repr ...
... mate change, air quality, and human health. Our ability to predict its formation and fate is hindered by uncertainties associated with one type in particular, organic aerosol (OA). Ambient OA measurements indicate that it can become highly oxidized in short timescales, but this is generally not repr ...
chapter 5 gases
... (c) is a weak electrolyte. A small amount of the compound dissociates into ions in water. When NaCl dissolves in water it dissociates into Na and Cl ions. When the ions are hydrated, the water molecules will be oriented so that the negative end of the water dipole interacts with the positive sodiu ...
... (c) is a weak electrolyte. A small amount of the compound dissociates into ions in water. When NaCl dissolves in water it dissociates into Na and Cl ions. When the ions are hydrated, the water molecules will be oriented so that the negative end of the water dipole interacts with the positive sodiu ...
Transition Metal-Modified Zirconium Phosphate Electrocatalysts for
... a number of general strategies, including increasing the number of active sites, increasing the intrinsic through a number of general strategies, including increasing the number of active sites, increasing the activity of each active site, and/or supporting the active material onto suppo ...
... a number of general strategies, including increasing the number of active sites, increasing the intrinsic through a number of general strategies, including increasing the number of active sites, increasing the activity of each active site, and/or supporting the active material onto suppo ...
BSc in Chemistry-CUCBCSS UG 2014-Scheme
... and developments of the modern society from time to time. To achieve this goal, the curriculum should be restructured by giving emphasis on various aspects such as the creativity of students, knowledge of current developments in the discipline, awareness of environmental impacts due to the developme ...
... and developments of the modern society from time to time. To achieve this goal, the curriculum should be restructured by giving emphasis on various aspects such as the creativity of students, knowledge of current developments in the discipline, awareness of environmental impacts due to the developme ...
Document
... is 0.113 at 298 K, which corresponds to a standard free-energy change of 5.4 kJ/mol. In a certain experiment, the initial pressures are PN2O4 = 0.453 atm and PNO2 = 0.122 atm. Calculate ΔG for the reaction at these pressures, and predict the direction in which the reaction will proceed spontaneously ...
... is 0.113 at 298 K, which corresponds to a standard free-energy change of 5.4 kJ/mol. In a certain experiment, the initial pressures are PN2O4 = 0.453 atm and PNO2 = 0.122 atm. Calculate ΔG for the reaction at these pressures, and predict the direction in which the reaction will proceed spontaneously ...
LABORATORY MANUAL GENERAL CHEMISTRY 120 Dr. Steven Fawl
... whereupon the original model is either modified or completely abandoned for a new model which describes the system more fully." Or, "When two elements combine the product has properties which are different from either of the reactants. This indicates that a new compound has been formed." DO NOT repe ...
... whereupon the original model is either modified or completely abandoned for a new model which describes the system more fully." Or, "When two elements combine the product has properties which are different from either of the reactants. This indicates that a new compound has been formed." DO NOT repe ...
Lewis acid catalysis
In Lewis acid catalysis of organic reactions, a metal-based Lewis acid acts as an electron pair acceptor to increase the reactivity of a substrate. Common Lewis acid catalysts are based on main group metals such as aluminum, boron, silicon, and tin, as well as many early (titanium, zirconium) and late (iron, copper, zinc) d-block metals. The metal atom forms an adduct with a lone-pair bearing electronegative atom in the substrate, such as oxygen (both sp2 or sp3), nitrogen, sulfur, and halogens. The complexation has partial charge-transfer character and makes the lone-pair donor effectively more electronegative, activating the substrate toward nucleophilic attack, heterolytic bond cleavage, or cycloaddition with 1,3-dienes and 1,3-dipoles.Many classical reactions involving carbon–carbon or carbon–heteroatom bond formation can be catalyzed by Lewis acids. Examples include the Friedel-Crafts reaction, the aldol reaction, and various pericyclic processes that proceed slowly at room temperature, such as the Diels-Alder reaction and the ene reaction. In addition to accelerating the reactions, Lewis acid catalysts are able to impose regioselectivity and stereoselectivity in many cases.Early developments in Lewis acid reagents focused on easily available compounds such as TiCl4, BF3, SnCl4, and AlCl3. The relative strengths of these (and other) Lewis acids may be estimated from NMR spectroscopy by the Childs method or the Gutmann-Beckett method. Over the years, versatile catalysts bearing ligands designed for specific applications have facilitated improvement in both reactivity and selectivity of Lewis acid-catalyzed reactions. More recently, Lewis acid catalysts with chiral ligands have become an important class of tools for asymmetric catalysis.Challenges in the development of Lewis acid catalysis include inefficient catalyst turnover (caused by catalyst affinity for the product) and the frequent requirement of two-point binding for stereoselectivity, which often necessitates the use of auxiliary groups.