BASIC CONCEPTS OF CHEMISTRY
... the nature of the process, resulting in a system of this state . The functions of the state are: 1) the internal energy of the system (U); 2) the enthalpy ( heat content ) of ( H) ; 3 ) the entropy (a measure of disorder) of the system (S); 4) the Gibbs’ free energy (G); 5) the Helmholtz’s free ener ...
... the nature of the process, resulting in a system of this state . The functions of the state are: 1) the internal energy of the system (U); 2) the enthalpy ( heat content ) of ( H) ; 3 ) the entropy (a measure of disorder) of the system (S); 4) the Gibbs’ free energy (G); 5) the Helmholtz’s free ener ...
sec chemistry may 2011 marking scheme
... • Unreactive / does not react with food • Removes O2 / slows the bacterial growth / slows the decay of the food / keeps food fresh / food preservation. • Slows the oxidation of food / retains the flavour of the food ...
... • Unreactive / does not react with food • Removes O2 / slows the bacterial growth / slows the decay of the food / keeps food fresh / food preservation. • Slows the oxidation of food / retains the flavour of the food ...
Structural Studies on Sulfated Glycopeptides from the Carbohydrate
... respectively (18, 19). This leaves two molar ratio of Xyl’ and Gal is 1:2, which suggests the presence anomeric signals still to be interpreted. One signal coincides of the partialstructure: -Gal@l-3Gal@l-4Xyl@l-O-Ser, i.e. the with that of Gal-3 H-1 at 6 = 4.664 ppm. Irradiation of the usually occu ...
... respectively (18, 19). This leaves two molar ratio of Xyl’ and Gal is 1:2, which suggests the presence anomeric signals still to be interpreted. One signal coincides of the partialstructure: -Gal@l-3Gal@l-4Xyl@l-O-Ser, i.e. the with that of Gal-3 H-1 at 6 = 4.664 ppm. Irradiation of the usually occu ...
Synthesis and Characterisation of N
... I hereby certify that I am the sole author of this thesis and that no part of this thesis has been published or submitted for publication. I certify that, to the best of my knowledge, my thesis does not infringe upon anyone’s copyright nor violate any proprietary rights and that any ideas, technique ...
... I hereby certify that I am the sole author of this thesis and that no part of this thesis has been published or submitted for publication. I certify that, to the best of my knowledge, my thesis does not infringe upon anyone’s copyright nor violate any proprietary rights and that any ideas, technique ...
Chapter 13 PowerPoint
... mainly product – equilibrium lies to the right A very small K means that the system at equilibrium will consist mainly of reactants – equilibrium position is far to the left The size of K and the time required to reach equilibrium are NOT directly related. Complete sample problem #5. ...
... mainly product – equilibrium lies to the right A very small K means that the system at equilibrium will consist mainly of reactants – equilibrium position is far to the left The size of K and the time required to reach equilibrium are NOT directly related. Complete sample problem #5. ...
Chapter 19
... Reduction: Cl 2 + 2e - → 2Cl Oxidation and reduction are complementary processes; oxidation cannot occur unless reduction also occurs. It is important to recognize and distinguish between oxidation and reduction. A memory aid might help you remember the distinction. The phrase Loss of Electrons is O ...
... Reduction: Cl 2 + 2e - → 2Cl Oxidation and reduction are complementary processes; oxidation cannot occur unless reduction also occurs. It is important to recognize and distinguish between oxidation and reduction. A memory aid might help you remember the distinction. The phrase Loss of Electrons is O ...
Chapter 6
... chemist studying the effect of pollution on spruce trees needs to know, or know where to find, the chemical differences between p‑hydroxybenzoic acid and p‑hydroxyacetophenone, two common phenols found in the needles of spruce trees. Your ability to “think as a chemist” is a product of your experien ...
... chemist studying the effect of pollution on spruce trees needs to know, or know where to find, the chemical differences between p‑hydroxybenzoic acid and p‑hydroxyacetophenone, two common phenols found in the needles of spruce trees. Your ability to “think as a chemist” is a product of your experien ...
Exam Edge Digital
... (iv) An atomic orbital is the region in space within which there is a high probability of finding an electron. (6) (v) Heisenberg’s Uncertainty Principle states that it is impossible to measure at the same time both the velocity (3) and the position (3) of an electron. ...
... (iv) An atomic orbital is the region in space within which there is a high probability of finding an electron. (6) (v) Heisenberg’s Uncertainty Principle states that it is impossible to measure at the same time both the velocity (3) and the position (3) of an electron. ...
Answers to Selected Exercises
... disorder of the system increases. (c) The process is spontaneous and therefore irreversible. (d) Since ¢H = 0, the process does not affect the entropy of the surroundings. 4.7 (a) At 300 K, ¢H = T¢S, ¢G = 0 and the system is at equilibrium. (b) The reaction is spontaneous at temperatures above 300 K ...
... disorder of the system increases. (c) The process is spontaneous and therefore irreversible. (d) Since ¢H = 0, the process does not affect the entropy of the surroundings. 4.7 (a) At 300 K, ¢H = T¢S, ¢G = 0 and the system is at equilibrium. (b) The reaction is spontaneous at temperatures above 300 K ...
advanced placement chemistry workbook and note set
... electrons and form ions, which are electrically-charged chemical species. The identity of the element does not change – only the electrical charge of the species changes. Recall from first-year chemistry that atoms lose or gain electrons based upon their metal or nonmetal character, and that the num ...
... electrons and form ions, which are electrically-charged chemical species. The identity of the element does not change – only the electrical charge of the species changes. Recall from first-year chemistry that atoms lose or gain electrons based upon their metal or nonmetal character, and that the num ...
step by step Stoichiometry
... asked to find the grams of HCl. These are the only two compounds we are concerned with in the balanced reaction. 2 HCl + Ca(OH)2 → CaCl2 + 2 H2O Write a conversion factor with these two compounds (the mol ratio): 2 mols HCl = 1 mol Ca(OH)2 ...
... asked to find the grams of HCl. These are the only two compounds we are concerned with in the balanced reaction. 2 HCl + Ca(OH)2 → CaCl2 + 2 H2O Write a conversion factor with these two compounds (the mol ratio): 2 mols HCl = 1 mol Ca(OH)2 ...
Chapter One Hemilabile Ligands in Transition
... examples of these include NH3, H2O, or F- which are known as hard ligands.1 The hard metal ions such as Cr3+ and Al3+ are low in electron density and require good σdonor ligands. Low oxidation state metals such as Ag+, Hg2+, which are soft metals, tend to form strong complexes with unsaturated or po ...
... examples of these include NH3, H2O, or F- which are known as hard ligands.1 The hard metal ions such as Cr3+ and Al3+ are low in electron density and require good σdonor ligands. Low oxidation state metals such as Ag+, Hg2+, which are soft metals, tend to form strong complexes with unsaturated or po ...
Organic Acids and Bases and Some of Their Derivatives
... We introduced the carbonyl group (C=O)—the functional group of aldehydes and ketones—in Chapter 14 "Organic Compounds of Oxygen". The carbonyl group is also found in carboxylic acids, esters, and amides. However, in these compounds, the carbonyl group is only part of the functional group. A carboxyl ...
... We introduced the carbonyl group (C=O)—the functional group of aldehydes and ketones—in Chapter 14 "Organic Compounds of Oxygen". The carbonyl group is also found in carboxylic acids, esters, and amides. However, in these compounds, the carbonyl group is only part of the functional group. A carboxyl ...
СУМСЬКИЙ ДЕРЖАВНИЙ УНІВЕРСИТЕТ
... All the oxides of one-valency metals (Na2О, K2O, Cu2O и др.) are basic. Most oxides of two-valency metals (СаО, ВаО, FeO и др.) are also basic. Exceptions: BeO, ZnO, PbO, SnO, which are amphoteric. Most oxides of three- and four-valency metals are ...
... All the oxides of one-valency metals (Na2О, K2O, Cu2O и др.) are basic. Most oxides of two-valency metals (СаО, ВаО, FeO и др.) are also basic. Exceptions: BeO, ZnO, PbO, SnO, which are amphoteric. Most oxides of three- and four-valency metals are ...
19_Worked_Examples
... (a) This process is spontaneous. Whenever two objects at different temperatures are brought into contact, heat is transferred from the hotter object to the colder one. (Section 5.1) Thus, heat is transferred from the hot metal to the cooler water. The final temperature, after the metal and water ach ...
... (a) This process is spontaneous. Whenever two objects at different temperatures are brought into contact, heat is transferred from the hotter object to the colder one. (Section 5.1) Thus, heat is transferred from the hot metal to the cooler water. The final temperature, after the metal and water ach ...
- Angelo State University
... • In the examples we’ve seen, we have assumed that all of the reactions “go to completion” — that is, that all reactant molecules are converted into products. In real life, some product is almost always lost due to small amounts of contamination present in the glassware, impurities in the reactants, ...
... • In the examples we’ve seen, we have assumed that all of the reactions “go to completion” — that is, that all reactant molecules are converted into products. In real life, some product is almost always lost due to small amounts of contamination present in the glassware, impurities in the reactants, ...
Chapter 16 Aqueous Ionic Equilibrium Lecture Presentation
... • It is a plot of pH versus the amount of added titrant. • The inflection point of the curve is the equivalence point of the titration. • Prior to the equivalence point, the known solution in the flask is in excess, so the pH is closest to its pH. • The pH of the equivalence point depends on the pH ...
... • It is a plot of pH versus the amount of added titrant. • The inflection point of the curve is the equivalence point of the titration. • Prior to the equivalence point, the known solution in the flask is in excess, so the pH is closest to its pH. • The pH of the equivalence point depends on the pH ...
Theories in the Evolution of Chemical Equilibrium: Impli
... were constantly forming and decomposing in such a way that the amounts of all the substances involved remain constant. This dynamic balance was achieved by assuming an interchanging of atoms, equal in absolute number in each moment of time, taking place in opposite direction. Consequently, the relat ...
... were constantly forming and decomposing in such a way that the amounts of all the substances involved remain constant. This dynamic balance was achieved by assuming an interchanging of atoms, equal in absolute number in each moment of time, taking place in opposite direction. Consequently, the relat ...
Computational Study of protonation of ozone
... Optimization of geometrical parameters of molecular structures was carried out using a threeparameter exchange-correlation functional B3LYP and the basis set 6-311 ++ G (d, p). To confirm that the structures are minima on the potential energy surface, and to determine the zeropoint energy at the sam ...
... Optimization of geometrical parameters of molecular structures was carried out using a threeparameter exchange-correlation functional B3LYP and the basis set 6-311 ++ G (d, p). To confirm that the structures are minima on the potential energy surface, and to determine the zeropoint energy at the sam ...
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.