The Case Of Zero Change In Gibbs Free Energy
TECTechnics Classroom   TECTechnics Overview

The Case Of Zero Change In Gibbs Free Energy

What is the ΔG (change in Gibbs free energy) when liquid water changes phase to vapor at 100oC and 1 atm. Molar enthalpy of vaporization is 9720 cal.

The strings:

S7P7A72 (Dynamic Equilibrium)

The math:
Pj Problem of Interest is of type equilibrium (zero Gibbs free energy). This problem can be cast as a change problem but it is not because the primary problem of interest is the equilibrium established when the change in Gibbs free energy is zero. It is in this sense that the primary problem of interest is of type equilibrium.

The equation of interest is:
Change in Gibbs free energy = enthalpy change - T(entropy change)

So, ΔG = ΔH - TΔS -------------(1) where T is temperature in degrees Kelvin.

ΔS = q/T = ΔH/T = 9720/373 cal/mole oK

So, ΔG = 9720 - 373(9720/373) = 0.

A system is in equilibrium when ΔG = 0 and has no usable energy to perform work.

Math The Universe is composed of matter and radiant energy. Matter is any kind of mass-energy that moves with velocities less than the velocity of light. Radiant energy is any kind of mass-energy that moves with the velocity of light.
Periodic Table
Composition And Structure Of Matter
How Matter Gets Composed
How Matter Gets Composed (2)
Molecular Structure Of Matter
Molecular Shapes: Bond Length, Bond Angle
Molecular Shapes: Valence Shell Electron Pair Repulsion
Molecular Shapes: Orbital Hybridization
Molecular Shapes: Sigma Bonds Pi Bonds
Molecular Shapes: Non ABn Molecules
Molecular Orbital Theory
More Pj Problem Strings

Blessed are they that have not seen, and yet have believed. John 20:29

TECTechnic Logo, Kimberlee J. Benart | © 2000-2021 | All rights reserved | Founder and Site Programmer, Peter O. Sagay.