Thermodynamics

Demonstrate an initial appreciation of the process of mixing in terms of thermodynamic driving forces, and through calculations, decide whether various chemical components will be miscible.

-Raoult's law used to calculate - used calculate 2 component phase diagram (non volatile solutes) -works best for ideal solutions (don't react with surrounding, deltaS is positive) -pi=pi(vapour pressure when pure)xi(mole fraction) -Only really obeyed by very dilute solutions PV=NRT

Explain the importance of gradients of thermodynamic functions as driving forces for chemical processes.

-The products and reactants will always move towards the equilibrium where the gradient =0 as this is the most stable from of the crystal -phases are skipped when their entropy isn't low enough to be stable -This agrees with le Chateliers principle

Calculate changes in values of thermodynamic functions at phase diagrams, and rationalise these changes.

-Van't hoff eqaution (change in temp) lnk2-lnk1=deltaH/R[1/T1-1/T2] -Clausius caperyon equation lnP2-lnP1=deltaH/R[1/T1-1/T2]

State simple differential forms of the Gibbs free energy and relate these to chemical changes.

At standard conditions deltaG=RTnQ At non standard conditions= deltaG=deltaG*-RTlnK At increase of temp and pressure -Increase in temp increases S and the volume will have a positive value thus G increases -when pressure increases it has a greater effect on G when there is a larger volume -Phase most stable when T is lowest molar G energy

Specific heat capacity

Eh=CmdeltaT -At pure crystal deltaS=0 due to the regular structure -this can be shown via S=KblnW

Draw a simple phase diagram for a single component system and explain the existence of different phases. Interpret more general phase diagrams in these terms.

Phase diagram is pressure vs temp -different phases exist as these states have the lowest molar Gibbs energy -triple point is phase where all 3 phases can exist -Polymorph is a solid that can exist in different crystal forms (e.g chocolate) -Supercritical fluid-moves like a gas and absorbs like a fluid (CO2 and decaf) -Boiling point when vapour pressure can overcome atmospheric pressure

Function

State function: Is not influenced by the journey but by the product Path function: Is influenced by the direction of the reaction and not the products Closed system=transfer of heat but not mass between the system and the surroundings Open system=Transfer of heat and mass between the system and surroudings Isolated system= no transfer between the system and the surroundings

Be aware of the definition of the chemical potential as a molar Gibbs energy.

U-potnetial molar Gibbs energy for each component in system (deltaG=nAuA+nBuB) -U,G &H depend on composition -deltaG reaction differs in chemical potential at composition of temp (deltaS dependent on U mols)

Define the conditions for chemical equilibrium in terms of Gibbs energies, and describe and calculate the effect of varying conditions on chemical equilibrium with respect to the variation of Gibbs energy with p and T.

deltaG=deltaH-TdeltaS -dependent on temperature and pressure Under non-standard conditions -deltaG=SdeltaT -at constant pressure as S is always positive so decreases with increasing T -deltaG=RTlnP1/P2 - changed in pressure (the gases with larger volumes have larger impact on G)

2nd law of thermodynamics

deltaS=deltaQ/T Heat cannot be transfered from a cold body to a hot body spontaneously -heat absorbed as function of temperature deltaQ/deltaT -When the temp increases there is nore dissorder delta S= C(t)ln(T2/T1) -When the pressure increases the entropy decreases as the particles are forced to bond to each other delta S=RTln(P2/P2)

State the simple differential form of the First Law of Thermodynamics and relate this to heat capacities;

deltaU=deltaQ- pdeltaT (1st law of thermodynamics) -Energy can neither be created or destroyed -U is influenced by work and heat -depends on volume of gas exchange and pressure of system H=U-pV (work is influenced by the pressure and volume) When there is transfer of heat from the surroundings to the