Upgrade to remove ads
Lecture questions exam 1
Terms in this set (74)
What is the first law of thermodynamics for both he universe as a whole and a system?
energy can not be created nor destroyed, it can only be changed from one form to another. dE=0
Black holes are a game changer.
How do we define the change in the internal energy of a system?
It is equal to heat flow into or out of the system - the work done on or by the system (dE=q-w)
How do you calculate the flow of heat into or out of the system?
q= number of moles
change in temperature
How do you calculate the mechanical (PV) work (w) done on or by a system?
w= Pressure * change in Volume
Define enthalpy (H) mathematically?
H = PV + E
PV is mechanical work
E is energy
What is the enthalpy of formation?
The constant-pressure heat required to forma a chemical compound from the elements ( in their most stable form) at standard conditions.
What is the enthalpy of formation of an element in its most stable form under standard condition?
What is the enthalpy of reaction?
the quantity of energy transferred as heat during a chemical reaction
How do we use enthalpy's of formation to calculate enthalpy changes of reactions?
dHrxn = sum of products' enthalpies - sum of reactants' enthalpies
How is dS defined and calculated?
The change in "randomness" of the reaction
dS = q/T
What is the second law of thermodynamics?
dS universe > 0 for any process. The universe is always increasing in randomness
Define dG and explain how it can be used to determine whether a reaction will occur spontaneously?
It is the change in free energy of a system.
dG = dH - T*dS
dG < 0 means the system reacts spontaneously
dG > 0 means the system doesn't react spontaneously
What is the Gibbs free energy of formation for a compound (dGf^o) and how can it be used to calculate the Gibbs free energy of a reaction?
analogous to the enthalpy of formation.
- the change in free energy when a compound is formed from its elements in their most stable form under a standard set of conditions
dGrxn= sum of dG products - sum of dG reactants
What is the rate of change of G with respect to T (dG/dT) equal to?
What is the rate of change of G with respect to P (dG/dP) equal to?
Assuming that dSrxn is approximately constant, how do we estimate the value of dGrxn at different temperatures?
Assuming that dVrxn is approximately constant, how do we estimate the value of dGrxn at different pressures?
Define thermodynamic equilibrium
How do we use G to predict when a mixture of reactants and products are at equilibrium?
Define chemical potential mathematically and verbally
What can we say about chemical potentials of the same component in two different phases at equilibrium?
Define an ideal solution
How do you use chemical potentials to calculate the Gibbs free energy change (dGrxn) of a reaction?
What is the expression that gives the chemical potential of a component of an ideal solution?
How do you write the equilibrium constant (K) in terms concentration of those components in a solution?
What is the relationship between the equilibrium constant for a reaction and dG^o for that reaction?
What are the typical standard state compositions for a solute, solvent, and a solid?
Give the equation for the chemical potential of a component in a non ideal solution
What is the relationship between the activity of a component and it's concentration (include definition of activity coefficient)?
Write the equilibrium constant relationship in terms of activities
In what sense is thermodynamic "effective" composition?
What is fugacity?
What are some sources of non-ideality for ions in aqueous solutions?
How do we calculate ionic strength?
How do we use the Debye-Hückel model to calculate activity coefficients?
What are the limitations of the Debye-Hückel model?
How do we use the Truesdell-Jones model to calculate activity coefficients?
What limitations do the Truesdell-Jones model?
What models do we use to calculate activity coefficients at very high ionic strengths?
How do we use debye-huckel model to calculate activity coefficients
What are the limitations of the debey-Huckel model
How do we use the truesdell-jones model to calculate activity coefficients
What are the limitations of the truesdell-jones model
What models do we use to calculate activity at very high ionic strengths
how do the activity coefficients of uncharged species vary with ionic strength
what is the ion activity product and how can it be used to determine whether a solution is saturated, under saturated or over saturated with respect to a mineral
Define a neutral, acidic, and basic solution and explain how and why the boundaries between these vary with temperature
what is an acid
what is pKa
what is a monoprotic acid, a diprotic acid, and a triprotic acid
given pH how would you calculate the ratios of the dissociation products of acids (for example aHCO3/aH2CO3 and aCO3/aHCO3)
What is a strong acid and what is the most important strong acid in natural systems?
What is a weak acid and what are the most important weak acids in natural systems?
What is silicic acid and how is it formed in natural systems
what is a base?
What is pKb
how (in detail) can you calculate the pH of rainwater in equilibrium with a given concentration of CO2 in the atmosphere
why, although most rain water is mildly acidic, is most surface water mildly basic?
What are the equations and procedures are used to calculate the pH in equillibrium with the atmosphere and dolomite
when calculating the pH of natural waters what is the difference between open and closed system?
what does acidity measure
what is Ca quantitatively
What does alkalinity measure
What is Cb quantitatively
How do you express Ca or Cb in milli-equivalent per liter (meq/L)
How are alkalinity and acidity determined empirically
What is buffering?
What is henderson-hasselbach equation and what is it used for
what is the buffering index
Be able to indentify and use the buffering index equations for monoprotic and diprotic acids
what does Eh measure
Explain how oxidation-reduction reactions can be used to make a batery and be able to use basic thermodynamic data to calculate the emf of that battery
Use the nernst equation to calculate E
YOU MIGHT ALSO LIKE...
AP Chemistry Chapter 5
Chm 116 Exam #1: ch 6 & 18
Chemistry Chapter 6
OTHER SETS BY THIS CREATOR
Petrology quiz 3
Petrology Quiz 2
Mineralogy Final Exam
OTHER QUIZLET SETS
Lab Exam 4