Summary
Summary Thermodynamics
- Module
- Pharmacy - Physical pharmacy
- Institution
- University Of East Anglia
Pharmacy - physical pharmacy 1st semester Bullet points, key notes, images and diagrams
[Show more]
Seller
Follow
Content preview
Physical PharmacyLecture 1 Thermodynamics
Temperature Scale
Kelvin (K) is used as an absolute temperature scale independent of the substance used
for reference
Derived from ideal gas at a low pressure
0K= no molecular motion
Heat is the process of transferring energy as a result of temperature difference
Temperature determines which way energy flows- from high to low
Ideal Gases
Obeys the relation PV=nRT
They don’t interact and occupy no volume
Partial Pressures
Pj=ΣPA
PA=XAP
XA=nA/Σni
Partial pressures of a mixture added together equal the total pressure of gases
Types of System
Adiabatic= no heat transfer q=0
Diathermal=heat transfer
Isothermal= constant T
Open system= energy and matter exchanged with the surroundings
Closed system= energy exchanged but not matter with the surroundings
Isolated system= energy and matter isn’t exchanged with the surroundings
Conservation of Energy
U=total energy of a system
Energy lost by the system=Energy gained by the surroundings (vice versa)
Closed system U=ΔU=q+w
Isolated ΔU=0 as q and w are constant
Work is the process of moving against an opposing force and the energy transfer is
uniform
ΔV=Vf-Vi
When w=0 it’s free expansion
When the pressure outside the system is slightly lower than the internal pressure-
maximum work takes place
Calorimetry
qv=CΔT
Burn known mass of substance to get known energy so ΔT=C
Differential scanning calorimeter (DSC)
DSC compares to reference sample but they’re heated the same so the energy change is
measured
State Functions
State function- dependant on the physical state of the substance
Path function- dependant on how the substance changed to a physical state (q and w)
, Lecture 2 Enthalpy
Enthalpy
H=U+PV where P is constant
Measures enthalpy changes- exothermic and endothermic (making bonds and breaking
bonds/ releasing energy and taking in energy)
Measured at standard states and conditions 298K and 1 bar
Enthalpy Change of Formation
Is the standard reaction enthalpy for the formation of a compound from its elements
under standard states and conditions
Elements enthalpy=0
Enthalpy Change of Combustion
Is the standard reaction enthalpy for complete oxidation of an organic compound to if
only C, H and O present and N2
Hess’s Law
Any chemical reaction that is independent of path and any intermediate reactions may
occur. Its initial reactants and final products which determine either ΔH or ΔU
The standard enthalpies of an overall reaction is the sum of the standard enthalpies of
the individual reactions into which a reaction may be divided.
Heat Capacity
C=q/ΔT
C is the measure of temperature change in a body produced by an increment of heat
Either carried out at a constant volume or pressure
Extensive property (2kg has 2x the heat capacity of 1kg)
Lecture 3 Entropy
Entropy
The entropy of an isolated system increases in the course of a spontaneous change
Degrees of disorder is related to the transfer of energy as heat
Heat causes a change in orderliness whereas work has no effect
At high temperatures a small increase in temperature has a very small effect on entropy
Entropy change= products-reactants
Entropy at 0K
Third law- a pure, perfect crystal at 0K has zero entropy
Lecture 4 Gibbs Free Energy
Free Energy
At a constant temperature and pressure
ΔG<0 it’s spontaneous
Only changes in ΔG can be measured
Gibbs energy of formation- ΔrGm=ΔG products-ΔG reactants
ΔrGm of elements=0
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller alexd1. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for £2.99. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
79373 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy revision notes and other study material for 14 years now