# CH0002 - Lecture 3

 The flashcards below were created by user james14hunter on FreezingBlue Flashcards. Another Gibbs free energy equation using the Equilibrium constant ΔGo = -RT lnK Thermodynamics tell us whether or not a reaction is ... and ... but it cannot tell us ... ...spontaneous...how far the reaction will go...how fast it will be What does Kinetics tell us? How quickly a reaction will take place. i.e. the rate of reaction. What is the rate? Rate = Change in concentration / Time What can you use to measure the concentration? Volumetric methods - Change in volume of gas or increase in pressureGravimetric methods - Change in mass (if a gas is consumed or evolved by the reaction)Instrumental methods -  Change in physical property which correlates with concentration. e.g colour, electrical conductivity, pH For a reaction  aA + bB --> cC + eE What is the rate? rate =-1/a x d[A]/dt   = -1/b x d[B]/dt   = +1/c x d[C]/dt   = +1/e x d[E]/dt  Where t = timeWhere d = change in The rate quation for a chemical reaction shows... ...how the rate depends on the concentrations of the various reactants and products What is the rate equation? rate = d[A]/dt = -k[A]n Where k is the rate constant and n is the reaction order. The minus sign indicates that the concentration of A falls with time. i.e. it is a reactant not a product In the rate equation, what do the powers to which the concentrations are raised indicate? The individual orders of reaction. Rate = (with powers) Rate = k[A]x[B]y[C]z Total order of reaction is given by... sum of the individual orders. Total order = x+y+z First order Units Rate = k[A]1Mol dm-3s-1 = k(mol dm-3)1s-1 = k Second order units Rate = k[A]2Mol dm-3s-1 = k(mol dm-3)2dm3mol-1s-1 = k Authorjames14hunter ID260335 Card SetCH0002 - Lecture 3 DescriptionCH0002 - Lecture 3 Updated2014-02-05T10:45:39Z Show Answers