Chemical reactions Flashcards
What is a phase diagram
graphical representation of the physical states of a substance under different conditions
What is the critical point in a phase diagram
point in temperature and pressure on a phase diagram where the liquid and gaseous phase of a substance merge together into a single phase
What does temperature change depend on
heat capacity/molar heat capacity
Ideal gas law equation
PV =nRT
What is the law of thermodynamics
matter has an energy content, heat is equivalent to mechanical energy, energy content can only be changed by heat exchange and work with environment
What does change in enthalpy result from
removing heat or be work
Which vairables can energy content be described from
pressure, volume, temperature, amount
What is Hess’ law
The enthalpy of a reaction is equal to the sum of the enthalpies of the reactions into which it may be divided.
*The enthalpy of a reaction is independent of the route taken
What is the second law of thermodynamics
state of matter described by energy and entrpy
Gibbs free energy
G = H - (Tx S)
What does G need to be for the reaction to occur spontaneously
<0
delta G calculations for phase transitions
G = -z.F.deltaE
Delta G calculation accessible in electrochemical reactions
G = - RTInK
What control is a reaction under when activation energy is not met compared to when it is
Ea met - thermodynamic control. Not - kinetic control
Rate constant formula
Z.e - Ea/RT
