GCE Chemistry SAMs 2009 onwards pdf
... Given that the standard enthalpy change of formation of liquid ethanol is –248kJmol-1 calculate the enthalpy change for the conversion of one mole of liquid ethanol to one mole of gaseous ethanol at 298 K. ...
... Given that the standard enthalpy change of formation of liquid ethanol is –248kJmol-1 calculate the enthalpy change for the conversion of one mole of liquid ethanol to one mole of gaseous ethanol at 298 K. ...
Physical Chemistry 1.pdf
... the chemist to predict whether or not a reaction will occur when reactants are brought together under a specific set of conditions. Indeed industrial chemists often place more emphasis on speeding up the rate of a reaction than on its percentage yield. Organic chemists use kinetic studies to determi ...
... the chemist to predict whether or not a reaction will occur when reactants are brought together under a specific set of conditions. Indeed industrial chemists often place more emphasis on speeding up the rate of a reaction than on its percentage yield. Organic chemists use kinetic studies to determi ...
chm 205 - National Open University of Nigeria
... pm. Here you may note that SiC also has the same structure but the alternate atom in it is Si in place of carbon. In diamond, the strong covalent bonds formed within the giant macromolecule result in a structure which is without any mobile electrons and thus it behaves as an insulator. The rigid, th ...
... pm. Here you may note that SiC also has the same structure but the alternate atom in it is Si in place of carbon. In diamond, the strong covalent bonds formed within the giant macromolecule result in a structure which is without any mobile electrons and thus it behaves as an insulator. The rigid, th ...
Review Unit: Chemistry Review
... process by comparing the results they predicted with their experimental results. Scientists make predictions that can be tested by performing experiments. Experiments that verify predictions lend support to the concepts on which the predictions are based. We try to explain events in order to underst ...
... process by comparing the results they predicted with their experimental results. Scientists make predictions that can be tested by performing experiments. Experiments that verify predictions lend support to the concepts on which the predictions are based. We try to explain events in order to underst ...
First Law of Thermodynamics
... the reactants and products, not on the manner in which they react! This is an important property because it allows us to determine ΔE for a reaction using any path - even one that is unreasonable - as long as the reactants and products remain the same. Both q and w are path dependent, so they are no ...
... the reactants and products, not on the manner in which they react! This is an important property because it allows us to determine ΔE for a reaction using any path - even one that is unreasonable - as long as the reactants and products remain the same. Both q and w are path dependent, so they are no ...
4.6 M - Thierry Karsenti
... Entropy (S). A direct measure of the degree of disorder or randomness of a system. Equilibrium. A condition in which an infinitesimal change in a variable in the opposite direction results in opposite change in the state. In chemical reactions, it represents the situation in which the reactants and ...
... Entropy (S). A direct measure of the degree of disorder or randomness of a system. Equilibrium. A condition in which an infinitesimal change in a variable in the opposite direction results in opposite change in the state. In chemical reactions, it represents the situation in which the reactants and ...
GCE Chemistry Specification (From 2015 - WALES ONLY
... is a requirement of all A level specifications that learners must demonstrate a holistic understanding of the links between different areas of content. In practice, this means that some questions set in A2 units will require learners to demonstrate their ability to draw together different areas of k ...
... is a requirement of all A level specifications that learners must demonstrate a holistic understanding of the links between different areas of content. In practice, this means that some questions set in A2 units will require learners to demonstrate their ability to draw together different areas of k ...
Chem. 1310 Fall 2005 Final Exam-white ... Name _________________________________ Section Number ___________________
... c. equal to that of a more concentrated solution of NaBr(aq). d. equal to that of the pure NaBr (s). e. none of these. Answer: b 25. As the equilibrium state of a chemical reaction is approached, a. the rate of the forward reaction approaches zero. b. the rate of the reverse reaction approaches zero ...
... c. equal to that of a more concentrated solution of NaBr(aq). d. equal to that of the pure NaBr (s). e. none of these. Answer: b 25. As the equilibrium state of a chemical reaction is approached, a. the rate of the forward reaction approaches zero. b. the rate of the reverse reaction approaches zero ...
unit-4-notes-1_enthalpy-and-entropy
... 2. Letting material into or out of the system will affect rates so a system at equilibrium is a closed system. 3. Again, consider the equilibrium reaction: N2O4 2 NO2 In the example that we did to construct the graphs, we had started with pure N2O4 and no NO2. The forward reaction rate was high at t ...
... 2. Letting material into or out of the system will affect rates so a system at equilibrium is a closed system. 3. Again, consider the equilibrium reaction: N2O4 2 NO2 In the example that we did to construct the graphs, we had started with pure N2O4 and no NO2. The forward reaction rate was high at t ...
Theoretical Investigation of the Water
... notation, the interfacial oxygens (Oint) are those top layer oxygens that are the nearest neighbor to the Pt cluster while surface oxygens (Os) are the other top layer oxygens. In our notation, OHs means that hydrogen has made hydroxyl group with the surface oxygen. The highlighted area corresponds ...
... notation, the interfacial oxygens (Oint) are those top layer oxygens that are the nearest neighbor to the Pt cluster while surface oxygens (Os) are the other top layer oxygens. In our notation, OHs means that hydrogen has made hydroxyl group with the surface oxygen. The highlighted area corresponds ...
Rates of Reaction
... – If doubling the concentration had a quadrupling effect on the rate, one would deduce it was a second-order dependence. – A doubling of concentration that results in an eight-fold increase in the rate would be a thirdorder dependence. Copyright © Houghton Mifflin Company.All rights reserved. ...
... – If doubling the concentration had a quadrupling effect on the rate, one would deduce it was a second-order dependence. – A doubling of concentration that results in an eight-fold increase in the rate would be a thirdorder dependence. Copyright © Houghton Mifflin Company.All rights reserved. ...
Chapter 1 – Reaction Kinetics Answer Key
... significant than the pressure as we are very close to sea level. This means molar volume is likely a bit smaller than 24.5 L/mol (or 26.5 L/mol for trial two). Dividing by a smaller number would lead to a LARGER MASS of zinc expected. 1.2 Review Questions (page 25) 1. Factors affecting heterogeneous ...
... significant than the pressure as we are very close to sea level. This means molar volume is likely a bit smaller than 24.5 L/mol (or 26.5 L/mol for trial two). Dividing by a smaller number would lead to a LARGER MASS of zinc expected. 1.2 Review Questions (page 25) 1. Factors affecting heterogeneous ...
Equilibrium Booklet - mrstorie
... 3. Chemists have determined the equilibrium constants for several reactions. In which of these reactions are the products favoured over the reactants? a. KC = 1.0×102 ...
... 3. Chemists have determined the equilibrium constants for several reactions. In which of these reactions are the products favoured over the reactants? a. KC = 1.0×102 ...
Unit 4 - Chemical Equilibrium
... _ _ _ _ _ _ _ reaction gets gradually faster. It follows that there must come a time when the reactions are happening in both _ _ _ _ _ _ _ _ _ _ at the same _ _ _ _ and the _ _ _ _ _ _ _ _ _ _ of reactants and products stop changing. This balanced situation is called _ _ _ _ _ _ _ equilibrium. It c ...
... _ _ _ _ _ _ _ reaction gets gradually faster. It follows that there must come a time when the reactions are happening in both _ _ _ _ _ _ _ _ _ _ at the same _ _ _ _ and the _ _ _ _ _ _ _ _ _ _ of reactants and products stop changing. This balanced situation is called _ _ _ _ _ _ _ equilibrium. It c ...
Reduction of nitrogen compounds in oceanic basement and its
... Zeolites like phillipsite coexist with smectite and almost always with mafic glass [7]. The term palagonite is normally used in reference to a bulk sample of metabasite which contains a mixture of palagonitized glass, authigenic minerals like smectite, corrensite, zeolites, carbonates and Fe-Ti oxid ...
... Zeolites like phillipsite coexist with smectite and almost always with mafic glass [7]. The term palagonite is normally used in reference to a bulk sample of metabasite which contains a mixture of palagonitized glass, authigenic minerals like smectite, corrensite, zeolites, carbonates and Fe-Ti oxid ...
PURPOSE: To determine the value of the equilibrium constant for a
... Equilibrium results when the two reactions occur at equal rates. The ions are dissociating into solution at the same rate that the ions crystallize into the solid. The concentration of the ions in the solution remains constant. We may model this as the breaking and forming of the ionic bond between ...
... Equilibrium results when the two reactions occur at equal rates. The ions are dissociating into solution at the same rate that the ions crystallize into the solid. The concentration of the ions in the solution remains constant. We may model this as the breaking and forming of the ionic bond between ...
Study materials of Chemistry for class XII
... Q12. Pure silicon is an insulator. Silicon doped with phosphorus is a semiconductor. Silicon doped with gallium is also a semiconductor what is the difference between the two semiconductors? 2M Ans. In pure silicon all electrons are involved in bonds formation. The bond formed is strong and cannot b ...
... Q12. Pure silicon is an insulator. Silicon doped with phosphorus is a semiconductor. Silicon doped with gallium is also a semiconductor what is the difference between the two semiconductors? 2M Ans. In pure silicon all electrons are involved in bonds formation. The bond formed is strong and cannot b ...
Stoichiometry: Predicting Amounts in Reactions
... Stoichiometry is the process of determining how much product is made or how much reactant is needed during a chemical reaction. As we know, in chemical reactions atoms are conserved. We show thi ...
... Stoichiometry is the process of determining how much product is made or how much reactant is needed during a chemical reaction. As we know, in chemical reactions atoms are conserved. We show thi ...
PREPARMACY PHYSICAL CHEMISTRY THERMOCHEMISTRY
... Heat of reaction or enthalpy of reaction The heat (enthalpy) of reaction is simply the amount of heat absorbed or evolved in the reaction. Its value depends upon the number of moles of the reactants which have reacted in the given chemical reactions. Thus, Heat of reaction may be defined as the amo ...
... Heat of reaction or enthalpy of reaction The heat (enthalpy) of reaction is simply the amount of heat absorbed or evolved in the reaction. Its value depends upon the number of moles of the reactants which have reacted in the given chemical reactions. Thus, Heat of reaction may be defined as the amo ...
M.Sc. Chemistry - Periyar University
... Fischer, Newman and Sawhorse projections and their interconvertion. Optical activity in the absence of chiral carbon – biphenyls, allenes and spiranes – R and S notations. Chirality due to helical shape, trans cyclooctene. E – Z isomerism of olefins containing one double bond and more than one doubl ...
... Fischer, Newman and Sawhorse projections and their interconvertion. Optical activity in the absence of chiral carbon – biphenyls, allenes and spiranes – R and S notations. Chirality due to helical shape, trans cyclooctene. E – Z isomerism of olefins containing one double bond and more than one doubl ...
Significant Figures
... significant figures and are called exact numbers. An example would be a whole number from a balanced equation: 6.021 x 4/2 = 12.04 where 4/2 is perhaps the stoichiometric ratio of product to reactant. Since both 4 and 2 are exact numbers they can be considered to each have more significant figures t ...
... significant figures and are called exact numbers. An example would be a whole number from a balanced equation: 6.021 x 4/2 = 12.04 where 4/2 is perhaps the stoichiometric ratio of product to reactant. Since both 4 and 2 are exact numbers they can be considered to each have more significant figures t ...
updated chem cp final review key
... f. Adding an enzyme Increases rate of reaction g. Breaking a reactant into smaller pieces Increases rate of reaction 43. Know what conditions are true of a chemical reaction at equilibrium. (1) rates of forward and reverse reactions are equal. (2) The concentrations of all substances involved stop ...
... f. Adding an enzyme Increases rate of reaction g. Breaking a reactant into smaller pieces Increases rate of reaction 43. Know what conditions are true of a chemical reaction at equilibrium. (1) rates of forward and reverse reactions are equal. (2) The concentrations of all substances involved stop ...
Thermodynamics ppt
... Entropy (S) Considerations: 1. S(s) < S(l) << S(g) 2. There is more entropy at higher temperatures and/or larger volumes (lower pressures) 3. The more bonds per molecule the greater the positional probability ex: CH4 > H2 4. If there are the same number of atoms in the molecules/elements; then the o ...
... Entropy (S) Considerations: 1. S(s) < S(l) << S(g) 2. There is more entropy at higher temperatures and/or larger volumes (lower pressures) 3. The more bonds per molecule the greater the positional probability ex: CH4 > H2 4. If there are the same number of atoms in the molecules/elements; then the o ...
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.