Question

In: Chemistry

Which of the following are true for a spontaneous process in a system at constant temperature...

Which of the following are true for a spontaneous process in a system at constant temperature and pressure? I. ∆Ssys + ∆Ssurr > 0 II. ∆Gsys < 0 It is possible both or neither could be true, or just one.

Solutions

Expert Solution

Recall the 2nd law of thermodynamics:

The entropy of the UNIVERSE must INCREASE always for an spontaneous process, i.e. a process that occurs in real life.

Therefore, if this is true

then

dSuniverse = dSsystem + dSsurroundings > 0

then

Case I.

∆Ssys + ∆Ssurr > 0

This is true, if the total addition of all entropy is greater than 0 (positive/increases) then this will occur

Case II.

∆Gsys < 0

This is also true, since dGsystem can be modeled as:

dG system = dHsystem- T*dSsystem

then, if this is less than 0, there is enough free energy for the system to "occur" in the forward direction

the best answe ris BOTH are true


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