If I spend more than 45 minutes on it, you have permission to take a nap

* To provide a self-consistent way of predicting the “thermo-physical” properties of matter at a known temperature and pressure * To calculate if a chemical reaction will absorb or release heat * To calculate if a reaction will occur spontaneously * To calculate the efficiency of an engine * To calculate the volume of a gas * To calculate the equilibrium partitioning of a species among various phases

* The energy (U) contained within an atom, molecule, or group of molecules can be defined in absolute or relative terms * Absolute terms (from macro to micro) – the energy within a O2 gas molecule in earth’s atmosphere * Velocity of the Milky-way galaxy (translation energy) + * Velocity of the Solar system (translation energy) + * Velocity of the Earth orbit (translation energy) + * Velocity of the Earth rotation (translation energy) + * Velocity of the O 2 molecule in X-Y-Z motion (translation) + * Rotation of the O 2 molecule around its axis (rotational energy) + * Vibration of the O 2 molecule (vibrational energy)) * Orbital energy of the bonding electrons (electronic energy) * Intrinsic energy of the O 2 molecule (mC 2 )

* Eliminate the external energy’s applied to the atom. Set those values to zero and work from there. * Relative energy of an O2 molecule * Energy of 1 mole O2 at 0C and 1atm = 0 * Likewise for other elements/molecules at a given reference point * Energy of 1 mole H2 at 0C and 1atm = 0 OK – but before we get there, let’s start from the beginning

* Back as early as the 166o’s, Robert Boyle, using a novel J-tube manometer, measured the property of a gas and concluded that the pressure and volume vary inversely:

* Guillaume Amontons ( ), * qualitatively identified that gas volumes increased linearly with temperature. * proposed a gas volume extinction point (an absolute zero) * Jaques Charles ( ) * Gas volume and temperature are proportional (unpublished) * Joseph Louis Gay-Lussac ( ) * If a gas mass and pressure are held constant then the volume varies linearly with temperature. This is an equation of state. K is an equilibrium constant

Represent equilibrium for every chemical reaction “=“ sets equilibrium. Activities (concentration) of products and reactants are linked to system energy

* Knowing the energy of each component (species) will enable us to predict it relative activity (or concentration) * Therefore, a species energy is the ultimate property, not the equilibrium constant

The energies of each species at 25 C and 1 atm in pure water (G 25C,1atm ). These values can be found in reference books. If 1.0 mole of calcite reacts (dissolves) to form 1.0 mole of Ca +2 and CO 3 -2, the energy difference is: That is: KJ of energy must be added to the system in the form of heat, work, or entropy to dissolve one mole of CaCO 3 at 25C and 1atm.

The energies of each species at 100 C and 100 atm in pure water. These values must be computed from an equation of state. If 1.0 mole of calcite reacts (dissolves) to form 1.0 mole of Ca +2 and CO 3 -2, the energy difference is: KJ of energy must be added to dissolve one mole of CaCO 3 at 100C and 100atm.

The energies of each species at 25 C and 1 atm in pure water (G 25C,1atm ). These values can be found in reference books. If 1.0 mole of halite reacts (dissolves) to form 1.0 mole of Na +2 and Cl -, the energy difference is: That is: KJ of energy must be added to the system in the form of heat, work, or entropy to dissolve one mole of halite at 25C and 1atm.

* There are two ∆G’s * The Standard State ∆G o, which is a function of temperature and pressure * Chemical bonding * Work, Potential Energy * Entropy * The excess ∆G E, which is a function of other factors * Concentration * Electric fields * Solvent Dielectric constants Used to calculate the equilibrium constants Used to calculate the activity coefficients We are interested in G 0. G E is discussed in the Activity coefficient section

What is the standard State? The standard state refers to a thermodynamic value at a defined state (temperature, pressure and concentration) Aqueous: The hypothetical 1.0 molal solution extrapolated from infinite dilution 1 molal PropertyProperty

General Thermodynamic Equations Vapor-Aqueous

General Thermodynamic Equations Non-Aqueous Liquid-Aqueous

The evaluation of the following equation is central to any chemical modeling: This value is our goal This is true at 25 C only

Effects of Temperature

The energies of each species at 25 C and 1 atm in pure water (G 25C,1atm ). These values can be found in reference books. If 1.0 mole of halite reacts (dissolves) to form 1.0 mole of Na +2 and Cl -, the energy difference is: That is: KJ of energy must be added to the system in the form of heat, work, or entropy to dissolve one mole of halite at 25C and 1atm.

At 25C, At 100C,

Working since 1968, Helgeson, et.al., have found that the standard-state thermodynamic property of any species in water can be represented by a function with seven terms which have specific values for each species. These seven terms (a 1-4, c 1-2, and  ) are integration constants for volume (a), heat capacity (c ) and temperature and pressure properties of water (  ). They are independent of the data system used to obtain them.

For NaCl (halite): The fundamental equation for K sp Definition: The Solubility Product constant of a solid that is in equilibrium with its corresponding dissolved species in water It is derived from the thermodynamics properties of the solid and of the dissolved ions

The fundamental equation when used with a rigorous Equation of State, is accurate to 300C and 1500atm Log K for HCO 3 -1

An simplified thermodynamic equation that is useful to ~350K (75C) and 1atm. This is called the Van’t Hoff equation.

Curve fitting equation used when solubility data is available Useful tool and effective within the experimental region