Gibbs Free energy + Etc

• Entropy is the measure of disorder in a substance, the less ordered a substance the more disordered

  Substances at absolute zero have zero enthalpy
• Entropy change = sum of the entropy of the products - sum of the entropy of the reactants

  Units = J K-1mol-1
• Gibbs free energy = Enthalpy change - T Entropy change

  Convert entropy by /1000
• All feasible reactions have a positive entropy value
• Reaction is feasible if the value of Gibbs free energy is equal to or less than zero
• Define entropy

  Entropy is the measure of disorder in a substance
• What is the symbol for entropy and what is it measured in

  S

  J K^-1 mol^-1
• When the number of molecules increase

  Entropy increases
• When the temperature increases

  Entropy increases
• Equation for entropy change?

  Total Entropy = Sum of the entropy of products - sum of the entropy of reactants
• What is the symbol for Gibbs free energy? and what is it measured in?

  G

  kJ mol^-1
• If a process has a  ΔG <0 then the reaction is

  Feasible
• If a process has  ΔG > 0 then the reaction is

  Not Feasible
• Gibb's free energy equation

   Change in G = Enthalpy change - (T * Entropy change)

  Divide entropy by 1000 to be in J mol^-1 k^-1
• Endothermic reaction with a decrease in entropy is

  Never Feasible
• Exothermic reaction with a increase in entropy is

  Always feasible
• A EXOthermic reaction with a decrease in entropy is

  Feasible at lower temperatures
• A ENDOthermic reaction with a positive entropy change is

  Feasible at higher temperatures