factors affecting S of a chemical system Flashcards
what affects the entropy of a chemical system?
- change in temperature
- mixing of particles (a,b,c)
- change in phase
- change in the number of particles (esp for gaseous systems)
explain the relationship between temperature and a system’s entropy
when the temperature of a system is increased, the increase in entropy comes about the broadening of Boltzmann energy distribution, more ways of arranging energy quanta in the hotter system
OR more possible energy states in which the particles can adopt at a higher temp–> higher entropy
why is S(solid)< S(liquid)«_space;S(gas)
solid to liquid phase
melting: order in solid is destroyed, particles in a liquid are more randomly arranged and more disordered
liquid to gas
gaseous state is the most disordered state as gaseous particles can move freely and are the most randomly arranged
why does the entropy of a system increase when the number of particles in the system increases
more particles, more ways to arrange the particles and more ways to distribute the energy in the system, creating greater disorder in the system
(gaseous particles’ increase in moles will increase the entropy more significantly)
what are the three ways of mixing of particles
- mixing of gas particles
- mixing of liquid particles
- the dissolution of an ionic solid in water
what types of liquid mixing will cause greater disorder
liquids of similar polarities–> molecules are randomly mixed–> greater disorder than in unmixed
increase in entropy due to more ways for molecules to arrange themselves in the larger volume of solution
how can the dissolution of an ionic solid in water increase/decrease in disorder
disruption of crystal increases disorder since oppositely charged ions previously held in rigid lattice are now free to move about
hydration of ions can decrease disorder, putting hydrating water molecules in an orderly arrangment
