Download Chemistry 331 In Class Exercise Review for Final #1) (a) What are

Chemistry 331 In Class Exercise
Review for Final
#1) (a) What are the different ways in which energy can be distributed in a molecule (degrees of
freedom)?
(b) How can part (a) be treated in terms of simple quantum mechanics (be specific)?
(c) How can part (a) be treated experimentally (be specific)?
#2) What is the scientific basis for the absolute temperature scale?
#3) Below is a graph of compressibility vs. pressure for a number of real gases:
Which gas has the largest attractive force and which gas has the largest repulsive force and why?
Chemistry 331 In Class Exercise
Review for Final
#4) What is the law of corresponding states and why it important when describing real gases in terms of
cubic equations of state?
#5) Name three common attractive forces in molecular systems (the so called
they be used to determine the second viral coefficient (use words only).
#6) The van der Waal’s equation is given below:
P=
RT
a
− 2
(V − b) V
Give a physical interpretation of what the parameter a and b account for.
#7) State the first law of thermodynamics.
#8) State the second law of thermodynamics.
#9) State the third law of thermodynamic.
1
r6
forces) and how can
Chemistry 331 In Class Exercise
Review for Final
#10) Give an example, an observation, in which the first law of thermodynamics applies.
#11) Give an example, an observation, in which the second law of thermodynamics applies.
#12) What is the difference between system and surroundings.
#13) Using a reversible cyclic process as your example, explain why work is not a state function.
#14) Heat and work are two common ways in which energy is _____________.
#15) Describe what work is in terms of extending a spring. If the spring is the system, is the work positive
or negative?
#16) In molecular terms what is heat capacity.
#17) What is the difference between a reversible and irreversible process? Give examples of both.
Chemistry 331 In Class Exercise
Review for Final
#18) Given a system that contains an ideal gas, how would you describe the state of the system?
#19) True or False: (q+w) is not a state function.
#20) True or False: The ideal gas equation is an example of an equation of state.
#21) True or False: If a system undergoes a cyclic process ΔH ≠ 0.
#22) For the process below, how would one calculate ΔH?
#23) Define the what the following paths mean.
a) Isobaric
b) Isothermal
c) Isochoric
d) Adiabatic
e) Cyclic
#24) The change in Enthalpy at constant pressure is equal to ___________ and the change in Internal
Energy is equal to ___________ at constant volume.
#25) If a chemical reaction releases heat into the environment it is call ______________ and if the
chemical reaction absorbs heat from the environment it is called _____________.
Chemistry 331 In Class Exercise
Review for Final
#26) What is Hess’s Law?
#27) Using pictures and words describe the isothermal compression of an ideal gas in which a minimum
amount of work has been done on the system.
#28) Using words and equations give a detailed explanation of what heat and work is from a molecular
point of view (statistical).
#29) A monatomic ideal gas will cool as it undergoes an adiabatic expansion. Why?
Chemistry 331 In Class Exercise
Review for Final
#30) Use molecular ideas (ie. S = k ln(N) ) to describe the nature of entropy.
#31) In terms of the change in Gibbs free energy, when is a chemical process spontaneous, nonspontaneous, and when does it reach equilibrium?
#32) Given that dG = VdP – SdT, derive the expression
d G
( T ) = − H . This is the Gibbs-Helmholtz
dT
T2
equation and it describes how the Gibbs Free energy changes with temperature at constant
pressure.
Chemistry 331 In Class Exercise
Review for Final
#33) Find the Maxwell relation that comes for a consideration of Gibbs Free Energy.
#34) Which has the greater molar entropy under the same conditions; CO or CO2. Justify your answer.
#35) Arrange the following reactions according to increasing values of ΔSReaction.
(a)
(b)
(c)
(d)
S(s) + O2(g) → SO2(g)
H2(g) + O2(g) → H2O2(l)
CO(g) + 3H2(g) → CH4(g) + H2O(l)
C(s) + H2O(g) → CO(g) + H2(g)
#36) For a non-isolated system Helmoltz and Gibbs Energy can be used to predict whether a processes
is spontaneous or not. Why is this true?
Chemistry 331 In Class Exercise
Review for Final
#37) Write dU, dH, dA and dG in terms of their natural and independent variables.
#38) What is fugacity and why is it useful?
#39) Sketch a Solid-Liquid-Gas pressure vs. volume phase diagram and indicate the regions in which µgas
= µsolid, µgas = µliquid, µliquid = µsolid and µgas = µliquid = µsolid.
#40) In terms of dG, µliquid, and µgas, describe the conditions in which vaporization is a spontaneous
process.
Chemistry 331 In Class Exercise
Review for Final
#41) For ideal solutions mixing is always spontaneous while this is not so for non-ideal solutions. Why?
#42) Why is the equilibrium constant for a chemical reaction dependent on temperature only?
#43) What is Le Chateliers Principle?
#44) Indicate on the diagram below the range for the extent of reaction in which the forward reaction is
spontaneous.
Chemistry 331 In Class Exercise
Review for Final
#45) In terms of chemical potentials what is the condition for the following reaction to be spontaneous in
the forward direction.
aA + bB ↔ cC + dD
#46) Derive an expression for ΔGmix for the mixing of two ideal gases.
#47) Knowing that
ΔG = RT ln
Q
for a chemical reaction, where Q is the reaction quotient and K is the
K
equilibrium constant, when does the reaction come to equilibrium, when is the reaction spontaneous,
and when is the reaction non-spontaneous. Give your answers in terms of K and Q.
Chemistry 331 In Class Exercise
Review for Final
#48) The van’t Hoff equation is an expression that gives the temperature dependence of the equilibrium
constant. The vant’ Hoff equation is:
⎛K ⎞
ΔH o ⎛ 1 1 ⎞
ln ⎜ 2 ⎟ = −
⎜ − ⎟
R ⎝ T2 T1 ⎠
⎝ K1 ⎠
Using this information describe how you could determine whether a chemical reaction is endothermic
o
o
o
or exothermic and how you can extract ΔH , ΔS , and ΔG ?
#49) Given the phase diagram below, label each line and indicate which are described by the Claperyon
equation and and which are described by the Clausius-Claperyon Equation and why.
#50) On the curve below circle and label the part of the curve that obeys Raoult’s law and the part that
obeys Henry’s law.