Question

Under what circumstances may the properties of the system alone be used to identify the direction of spontaneous change?

Answer 1

The difference between spontaneous and non-spontaneous reactions are determined in the 2^nd law of thermodynamics. It is valuable to have the capacity to anticipate regardless of whether a procedure will be spontaneous, yet to do as such we have to discover some property of a system that will decide the bearing of spontaneous change. At first, one should seriously mull over the internal energy, U, of a system and estimate that it keeps an eye on a base. In any case, the First Law of Thermodynamics expresses that total energy is conserved in any procedure. This implies right off the bat that energy of an isolated system cannot change in any process, in conflict with our desire. Certain procedures happen spontaneously, for instance, cooling of a hot object to the temperature of the surroundings, and expansion of a gas to fill the volume accessible to it. There is a moment, more crucial issue with the speculation if the energy of a system diminishes in a spontaneous change, at that point by the First Law the energy of the surroundings must increase by the same amount, yet the two procedures are spontaneous. Consequently obviously changes in the internal energy of a system can't be the signpost of spontaneous change. Objects do not spontaneously become warmer than their surroundings because this would require the accumulation of excess thermal energy in the object. Gases do not spontaneously contract because to do so requires the chaotic motion of the gas particles to become ordered and localized in one part of the container.