Thermodynamics Flashcards
What does thermodynamics govern in pharmaceutical science?
1) partitioning of solute between immiscible solvents
2) solubility of drugs
3) drug receptor interactions
4) phase transitions
5) predict the position of eqm in a system
6) energy changes during reaction
What’s a chemical system?
The part of the universe with which we are studying
What’s surroundings?
The rest of the universe
What is thermodynamics?
Motion power of heat (movement of heat from one form to another)
What’s a function of State? (Variable)
It describes the state or condition of the system as it is now, without reference to its immediate history
A change in function of state (Delta X) is measured as…?
X FINAL- X INITIAL
What’s the character of a change of function of state?
INDEPENDENT of its path
How do we measure the internal energy of a system?
What’s delta T measured to?
Bomb calorimeter: measure heat change at constant volume (no work) during combustion.
0.001C
Define the enthalpy of formation
Delta H fT
Enthalpy change when 1 mole of compound is formed under standard condition from its constituent elements in their standard state!!
How can we create order of of disorder?
Re crystallisation event
When solution becomes solid crystal, entropy decreases whereas it generates heat (exothermic reaction), at a particular temperature, the difference between them is zero. Net change> disorder
The system entropy decreases
Delta G is?
A measure of the work done (energy) obtained from a reaction
Work that must be done on the compound to get the constituent elements back again
When does a system reach eqm?
When it has reached its minimum free energy G
What’s thermodynamic second law?
The spontaneous (irreversible) reactions are those INCREASE the entropy of the universe.
What would happen if S(system) +S(surroundings) >/ = 0
Spontaneous reaction (irreversible)
Reversible reaction
What’s the third law?
Absolute entropy:
The entropy of a PERFECT CRYSTAL at 0 K is ZERO
