CHM1046 Exam 2 Dr.Dillon Questions And Correct Answers Pass Guaranteed

chemical kinetics - correct answers the study of reaction rates, how reaction rates change under varying conditions and by which mechanism the reaction proceeds. Reactions can be spontaneous but - correct answers this does not mean they occur fast Kinetics - correct answers the study of reaction rates reaction rates - correct answers a measure of how quickly reactants turn into products rate laws are - correct answers how the rate depends on amounts of reactants integrated rate law - correct answers relationship between the concentrations of the reactants and time half life - correct answers length of time required for half of the radioactive atoms in a sample to decay Arrhenius equation - correct answers k=Ae^(-Ea/RT); relationship between rates and temperatures rate of reaction equals - correct answers change in concentration/change in time Factors that effect the rate of a reaction - correct answers increasing temperature, concentration of the reactants, surface area, catalysts, physical states, light, increased pressure X+Y=Z Rate of reaction=? - correct answers change in [Z]/change in time applicatios of kinetics - correct answers shelf life, drug metabolism, food preservation, radiation initial rates - correct answers rates measured at the beginning of the reaction, which is dependent on the initial concentrations of the reactants instantaneous rate - correct answers rates measured at any point during the reaction average rates - correct answers an overall rate measured over a period or time interval activation energy - correct answers Energy needed to get a reaction started rate of reaction depends on - correct answers collision frequency and collision energy Reaction occur the fastest when molecules are - correct answers colliding quickly Ina reaction, as the pressure increases - correct answers the space in which the particles are moving becomes smaller catalyst - correct answers substance that speeds up the rate of a chemical reaction Examples of catalysts - correct answers Nickel Iron Platinum rate law - correct answers k[A]^n; works when temp is constant differential rate law - correct answers shows how the rate of reaction depends on the concentration overall reaction order - correct answers the sum of all the exponents in a rate law expression 1st order reaction - correct answers rate=k[A] 2nd-order reactions of Class I - correct answers Reactions in which the rate varies with concentration of a single species, but the stoichiometric coefficient is 2. The rate varies with the reciprocal of the concentration, so a plot of 1/(concentration) versus time is linear. 2nd-order reactions of Class II: - correct answers Reactions in which the rate varies with the concentration of two species, each of which has a stoichiometric coefficient of 1. A plot of ln(concentration .A/concentration B) versus time is linear. higher order reactions - correct answers Reactions in which more than two species are involved, or one species reacts with stoichiometric coefficient 2 zero order reaction - correct answers rate is independent of the concentration of the reactant. units of k for zero order - correct answers mol/L*s units of k for first order - correct answers 1/s units of k for second order - correct answers L/mol*sec units for k third order - correct answers L^2/mol^2*s integrated rate law tells us - correct answers the concentration as a function of time know the chart in lecture 10 - correct answers half life formula for first order - correct answers ln(2)/k half life formula for second order - correct answers 1/k[A]0 half life formula for zero order - correct answers [A]0/2k collision theory - correct answers For a reaction to occur, the particles must collide, they must collide with the appropriate orientation, and they must collide with sufficient energy. poor orientation= - correct answers no reaction collisions need - correct answers sufficient energy/velocity Maxwell-Boltzmann distribution - correct answers Shows the spread of energies that molecules of gas or liquid have at a particular temperature Arhenius equation - correct answers k = Ae^(-Ea/RT) frequency factor - correct answers -"A" in Arrhenius equation -also known as "attempt frequency" -a measure of how often molecules in a certain reaction collide -units of s ^-1 Two-point form of Arrhenius equation - correct answers ln (k2/k1) = Ea/R (1/T1 - 1/T2) spontanueous proccesses - correct answers physical or chemical change that occurs with no outside intervention however some energy may be supplied to get the process in action (activation energy) cataysts do not affect - correct answers enthalpy Enthalpy - correct answers total energy of a system (difference between products and reactants) Increasing temperature increases - correct answers rate constant reaction mechanism - correct answers a series of elementary reactions that take place during the course of a complex reaction intermediates - correct answers Those reactants and products that appear only in an elementary reaction but not in the overall reaction unimolecular elementary reaction - correct answers product