Predicting Pharmaceutical stability Flashcards
what is thermodynamics?
energy and its transfer
allows for prediction of physical instabilities
allows to predict if chemical reactions will happen
what are the four law of thermodynamics?
the zeroth law: concept of temperature
first law:conservation of energy
second law:entropy principle
third law:absolute zero temperature
energy unit?
joules
what is potential energy
due to position
what is kinetic energy?
due to motion
what is bulk theory?
doesn’t consider molecular nature of matter
what is a system?
part of universe chosen to consider
what are surroundings?
everything else around the system
open system?
matter and energy can cross the boundary between system and surrounding
heat and matter can escape
closed system?
no matter can transfer through boundary
only heat can escape
isolated system?
no matter or energy transfer or heat
no heat and no matter can escape
what is work?
‘transfer of energy from one system to another moving its point of application in its own direction’
ordered movement of atoms
what is heat?
transfer of energy due to difference in temperature
disordered or chaotic movement of atoms
what are heat and work?
energy that’s in the process of being transferred
heat and work not stored they’re done on or done by matter
what is the zeroth law?
if A and B are in thermal equilibrium and B and C are in thermal equilibrium then A and C are equal to each other.
what are the movement of particles when heated like?
inter and intra molecular vibrations
trans and rotational motions
what is equation of work?
- opposing force * distance
what is Patm?
expansion of gas under constant external pressure
what is the quantity of q if energy is absorbed by the system?
positive +
what is the quantity of q if energy is evolved by the system?
negative -
what is the quantity of w when work is done on the system (compression)?
positive +
what is the quantity of w when work is done by the system (expansion)?
negative -
what is internal energy?
energy in a system
what is the first law of thermodynamics?
q + w = change in internal energy
what is the change in internal energy when no work is being done and only heat is involved in a closed system?
= C * change in temperature
what is the equation of the heat content of an open system?
= change in internal energy + pressure * change in volume
how can the internal energy of a system be reduced?
by the system transferring energy as heat
what is thermochemistry?
studying heat changes by chemical reactions
what are the standard conditions in thermochemistry?
pure, unmixed substances at 25°C at 1atm
what does the total enthalpy change depend on?
only on nature and state of products and reactants
why is the enthalpy of reactions hard to determine?
because its hard to isolate
what is Hess’ law?
when enthalpy of a reaction can’t be determined other enthalpies can be combined to calculate it
what is entropy?
how disordered a system is
what is the second law of thermodynamics?
in an isolated system entropy increases in a spontaneous process
only applies to isolated sytems
what is the second law of thermodynamics in open system?
entropy of the universe increases in a spontaneous process
what are spontaneous processes?
irreversible
entropy increases
what are reversible reactions?
finely balanced and always at equilibium
entropy doesn’t increase
what is the equation for entropy change?
q/T
what is the reason for change in entropy equation?
greater dispersion of energy with more heat and heat effects a cold reservoir more than a hot one
what is the third law of themodynamics?
‘the entropy of a perfectly crystalline material is 0 at T= 0K’
what happens to heat energy at T=0K?
thermal motion is elimintated
what is absolute temperature?
when no entropy and thermal motion is eliminated
what are the two driving forces for spontaneous change?
energy and entropy difference between initial and final states
what is the equilibrium constant?
[products]/[reactants]
what does it mean when K >1 at equilibrium?
products dominate reaction mixture
what does it mean when K < 1 at equilibrium?
reactants dominate reaction mixture
what does it mean when K =1 at equilibrium?
products and reactants are at equal abundance
what is the equation for delta G?
-RT ln K
what is the total entropy equal to in an open or close system?
entropy of surrounding + entropy of system
what is the equation of free energy at constant temperature and pressure?
enthalpy of reaction - T * change in entropy
what happens to the free energy in an open system in a spontaneous process?
decreases so gibbs energy always less than 0
what does delta G mean?
maximum work done that doesn’t include expansion and is done at a constant pressure and temperature
what does delta G less than 0 mean?
spontaneous process
what does delta G greater than 0 mean?
change won’t occur spontaneously
what does delta G equal to 0 mean?
system is at equilibrium
when will a system come to equilibrium?
when its reached its minimum free energy
what is the Van’t Hoff’s equation?
predicting pharmaceutical stabilities
part 5
slide 2
what is the gradient of 1/K and 1/T graph?
– deltaH / R
what does ATP stand for?
adenine triphosphate
what does ADP stand for?
adenine diphosphate
