ACS Physical Chemistry Thermochemistry Study Guide |100% Correct|

ACS Physical Chemistry Thermochemistry Study Guide |100% Correct| What is the third law of thermodynamics? *Ans* The entropy of a perfect crystal is zero. What is the second law of thermodynamics? *Ans* As a whole, the universe always tends towards increasing entropy. What is the relationship between number of microstates and entropy? *Ans* More microstates = higher entropy What is the relationship between temperature and entropy? *Ans* Temperature increases, entropy increases (direct) What is the relationship between atomic weight and entropy? *Ans* Heavier = increased entropy (direct) What happens to entropy when a substance is dissolved in another? *Ans* Entropy increases What is the relationship between moles of gas and entropy? *Ans* When moles of gas increase, entropy increases (direct) What is the relationship between free energy, enthalpy, and entropy? *Ans* deltaG(system)=deltaH(system)-TdeltaS(system) What does change in G measure? *Ans* The extent of the spontaneity of a process, and the useful energy available from it What is the relationship between work and spontaneous processes? *Ans* Spontaneous processes produce work What is the relationship between work and non-spontaneous processes? *Ans* Nonspontaneous processes require work What does -w mean? *Ans* Work is being produced - spontaneous What does a positive sign for w mean? *Ans* Work is required - non-spontaneous Can a change be spontaneous in both directions? *Ans*