thermodynamics- chemical equilibria

chemical potential

the quantity which allows us to define the dependence of the overall Gibbs free energy on the composition of the mixture

high chemical potential

addition causes free energy to increase a great deal- results in high free energy for a system

low chemical potential

addition causes free energy to increase only slightly

what does higher free energy of a system mean

higher free energy of a system= higher driver for spontaneous reaction

what will high chemical potential reactants tend to do

tend to form lower chemical potential products

does everything try to lose its free energy or gain free energy

lose freee energy to its surroundings

what is chemical potential actually saying

how much does the free energy increase by adding 1 mole of this substance to a solution

importance of chemical potential

enables us to predict the direction of different processes

change of free energy during reaction

• when a reaction occurs the system goes in the direction of high chemical potential to low until the net potentials of the products and reactants balance

• at this point the systems will be in equilibrium

chemical equilibria equation

K = [C]c[D]d/[A]a[B]b

le chateliers principle

when an external change is made to a system in equilibrium, the system will respond so as to oppose the change

increasing temperature in equilibrium

• endothermic

• restore the temperature by producing more products

• absorbs more heat energy

• equilibrium shifts to right

• more products therefore K increases

van’t Tofft equation

ln K2 = ln K1 + H/R (1/T1 - 1/T2)

what does van hot enable us to do

quantify the effect of temperature on equilibrium constant

how would the equilibrium constant change if the process is endothermic

• if the reaction is endothermic we go from T1<T2, then the right hand side is positive which means K2 is greater than K1

• the reaction will occur to a GREATER extent if you raise the temp.