key concepts of matter
... Key Concept 2: A chemical formula is the combination of all of the elemental symbols found within a substance. The atom numbers of each element are identified by subscripts to the right of the elemental symbol. Key Concept 3: A chemical equation shows the atom numbers and molecules making up the rea ...
... Key Concept 2: A chemical formula is the combination of all of the elemental symbols found within a substance. The atom numbers of each element are identified by subscripts to the right of the elemental symbol. Key Concept 3: A chemical equation shows the atom numbers and molecules making up the rea ...
Standard Enthalpy of Formation
... - must measure ΔH for the chemical reaction that forms the compound from its elements. ...
... - must measure ΔH for the chemical reaction that forms the compound from its elements. ...
The internal energy
... 1. In the reaction 2 H2(g) + O2(g) → 2 H2O(l), 3 mol of gas-phase molecules is replaced by 2 mol of liquid-phase molecules, so ∆ng = −3 mol. Therefore, at 298 K, when RT = 2.5 kJ mol−1, the enthalpy and internal energy changes taking place in the system are related by • Note that the difference is e ...
... 1. In the reaction 2 H2(g) + O2(g) → 2 H2O(l), 3 mol of gas-phase molecules is replaced by 2 mol of liquid-phase molecules, so ∆ng = −3 mol. Therefore, at 298 K, when RT = 2.5 kJ mol−1, the enthalpy and internal energy changes taking place in the system are related by • Note that the difference is e ...
Unit 4
... decomposition, single replacement and double replacement reactions. I) Combination Reactions In a combination reaction, two or more substances react to form a single product. The general form of this reaction is (A + B → AB). Some examples are shown below: 2Mg(s) + O2(g) → 2MgO(s) 2Na(s) + Cl2(g) → ...
... decomposition, single replacement and double replacement reactions. I) Combination Reactions In a combination reaction, two or more substances react to form a single product. The general form of this reaction is (A + B → AB). Some examples are shown below: 2Mg(s) + O2(g) → 2MgO(s) 2Na(s) + Cl2(g) → ...
unit (4) calculations and chemical reactions
... decomposition, single replacement and double replacement reactions. I) Combination Reactions In a combination reaction, two or more substances react to form a single product. The general form of this reaction is (A + B → AB). Some examples are shown below: 2Mg(s) + O2(g) → 2MgO(s) 2Na(s) + Cl2(g) → ...
... decomposition, single replacement and double replacement reactions. I) Combination Reactions In a combination reaction, two or more substances react to form a single product. The general form of this reaction is (A + B → AB). Some examples are shown below: 2Mg(s) + O2(g) → 2MgO(s) 2Na(s) + Cl2(g) → ...
Chapter 7 – Chemical Reactions and Energy Flow
... Despite extensive tables containing the standard enthalpy of formation for literally hundreds of chemical compounds, they are not sufficient. Many reactions are outside of the scope of the tables. However, we can approximate the energy by using the average bond energies for all of the chemical bond ...
... Despite extensive tables containing the standard enthalpy of formation for literally hundreds of chemical compounds, they are not sufficient. Many reactions are outside of the scope of the tables. However, we can approximate the energy by using the average bond energies for all of the chemical bond ...
Elements can be broken down by chemical reactions
... Change also has two categories: physical change and chemical change. The factor distinguishing one category form the other is whether or not a particular change results in the production of a new substance. Physical change is a change that does NOT result in the production of a new substance. If you ...
... Change also has two categories: physical change and chemical change. The factor distinguishing one category form the other is whether or not a particular change results in the production of a new substance. Physical change is a change that does NOT result in the production of a new substance. If you ...
Final review packet
... Organize and review all old exams and reading journals. Study sequentially from the beginning. You are responsible for all material. Divide your study time into short, intense sections. This can be more effective than studying continually for a long period of time. Study with a friend. Quiz ...
... Organize and review all old exams and reading journals. Study sequentially from the beginning. You are responsible for all material. Divide your study time into short, intense sections. This can be more effective than studying continually for a long period of time. Study with a friend. Quiz ...
Chem Curr - New Haven Science
... 1. Determine the molecular mass of a compound. 2. Determine empirical and molecular formulas for compounds. 3. Determine the chemical composition and write a compound’s formula by using percent composition and mole ratios. 4. Given data in mass or moles, calculate masses and yields of reactants and ...
... 1. Determine the molecular mass of a compound. 2. Determine empirical and molecular formulas for compounds. 3. Determine the chemical composition and write a compound’s formula by using percent composition and mole ratios. 4. Given data in mass or moles, calculate masses and yields of reactants and ...
Classwork – Nature, Properties, and Classification of Matter
... Classwork – Chemical Quantities (Stoichiometry) 1. Using sandwich making as an analogy to chemical reactions, show the balanced equation that requires 2 pieces of bread, 3 slices of meat and on slice of cheese to make 1 sandwich. 2. Using the ratios for the above process (reaction), show the balance ...
... Classwork – Chemical Quantities (Stoichiometry) 1. Using sandwich making as an analogy to chemical reactions, show the balanced equation that requires 2 pieces of bread, 3 slices of meat and on slice of cheese to make 1 sandwich. 2. Using the ratios for the above process (reaction), show the balance ...
reactions taking place within cells
... 1st law of thermodynamics Energy can’t be created or destroyed, only converted from one form to another Hess’s law H for a reaction is independent of the route it takes provided that the temperatures, pressures and physical states of the reactants and products are the same H of reverse reaction ...
... 1st law of thermodynamics Energy can’t be created or destroyed, only converted from one form to another Hess’s law H for a reaction is independent of the route it takes provided that the temperatures, pressures and physical states of the reactants and products are the same H of reverse reaction ...
Power Point for Equilibrium
... decomposes to brown NO2: N2O4(g) 2NO2(g). • At some time, the color stops changing and we have a mixture of N2O4 and NO2. • Chemical equilibrium is the point at which the rate of the forward reaction is equal to the rate of the reverse reaction. At that point, the concentrations of all species are ...
... decomposes to brown NO2: N2O4(g) 2NO2(g). • At some time, the color stops changing and we have a mixture of N2O4 and NO2. • Chemical equilibrium is the point at which the rate of the forward reaction is equal to the rate of the reverse reaction. At that point, the concentrations of all species are ...
Chemical Equilibrium Equilibrium A state where the reactants and
... Eventually the rates become _________________. Factors affecting equilibrium position: _____________ concentrations*** ________________ of reactants and products “____________________” of reactants and products. ***The factor to be addressed in this unit. ...
... Eventually the rates become _________________. Factors affecting equilibrium position: _____________ concentrations*** ________________ of reactants and products “____________________” of reactants and products. ***The factor to be addressed in this unit. ...
Transition state theory
Transition state theory (TST) explains the reaction rates of elementary chemical reactions. The theory assumes a special type of chemical equilibrium (quasi-equilibrium) between reactants and activated transition state complexes.TST is used primarily to understand qualitatively how chemical reactions take place. TST has been less successful in its original goal of calculating absolute reaction rate constants because the calculation of absolute reaction rates requires precise knowledge of potential energy surfaces, but it has been successful in calculating the standard enthalpy of activation (Δ‡Hɵ), the standard entropy of activation (Δ‡Sɵ), and the standard Gibbs energy of activation (Δ‡Gɵ) for a particular reaction if its rate constant has been experimentally determined. (The ‡ notation refers to the value of interest at the transition state.)This theory was developed simultaneously in 1935 by Henry Eyring, then at Princeton University, and by Meredith Gwynne Evans and Michael Polanyi of the University of Manchester. TST is also referred to as ""activated-complex theory,"" ""absolute-rate theory,"" and ""theory of absolute reaction rates.""Before the development of TST, the Arrhenius rate law was widely used to determine energies for the reaction barrier. The Arrhenius equation derives from empirical observations and ignores any mechanistic considerations, such as whether one or more reactive intermediates are involved in the conversion of a reactant to a product. Therefore, further development was necessary to understand the two parameters associated with this law, the pre-exponential factor (A) and the activation energy (Ea). TST, which led to the Eyring equation, successfully addresses these two issues; however, 46 years elapsed between the publication of the Arrhenius rate law, in 1889, and the Eyring equation derived from TST, in 1935. During that period, many scientists and researchers contributed significantly to the development of the theory.