CHE 1810 Spring 2014
What you need to know:
STUDY GUIDE : EXAM 1
CH 12 : SOLUTIONS
Phase diagram of water
Freezing (melting) point, normal freezing (melting) point Tnf
Boiling point, normal boiling point Tnb
n(solute)
m(solute)
m
; using n =
=
V (solution,L) M(solute)V (solution,L)
M
n(solute)
m(solute)
Molality: m(solute) =
=
m(solvent,kg) M(solute)m(solvent,kg)
n(solute)
Mole Fraction:
X(solute) =
n(solute) + n(solvent)
n(1)
n(2)
two solutes : X(1) =
;
X(2) =
n(1) + n(2) + n(solvent)
n(1) + n(2) + n(solvent)
Molarity:
M(solute) =
Mole Percent:
mol% = mole fraction*100
Note : Sum of mole fractions = X(1) + X(2) + …… = 1.00
Sum of mole percent = mol%(1) + mol%(2) + …… = 100.0
m(solute)×100
m(solute)×100
=
m(solute) + m(solvent)
m(solution)
m(1)×100
m(1)×100
=
two solutes : m%(1) =
etc
m(1) + m(2) + m(solvent) m(solution)
Mass Percent: m%(solute) =
Boiling point elevation :
with
Freezing point depression :
DTf = K f (solvent)m(solute)
with DTf = Tf (solvent) -Tf (solution) > 0
CH 13 : CHEMICAL KINETICS
Rxn :
aA + bB --> cC
Rate of rxn :
Rate of disappearance < 0
Rate of formation > 0
Rate of reaction r > 0
Rate law :
r = k[A]m [B]n
>0
D[A]
<0
Dt
D[C]
>0
rC =
Dt
1
1
1
r = - rA = - rB = rC
a
b
c
rA =
How to determine m, n, and k from experimental data
n = order of rxn with respect to A etc.
Order of rxn = m + n
Zero order rxn , rate law , integrated rate law , half life
First order rxn , rate law , integrated rate law , half life
Second order rxn , rate law , integrated rate law , half life
What to graph
Units of k
Calculations based on the integrated rate laws
G. Lind
Reaction profile
Activation energy
Arrhenius equation : k = Aexp[ -
Ea
]
RT
same as
lnk =
-
Ea 1
× + lnA
R T
How to determine Ea , A :
Graph : lnk versus 1/T when more than two experiments (straight line y = mx + b)
when only two experiments :
ln
k2 E a 1 1
=
( - )
k1
R T1 T2
solve for Ea
same as ln
k1 E a 1 1
=
( - )
k2
R T2 T1
same as ln
k1
E 1 1
= - a( - )
k2
R T1 T2
Reaction Mechanism, elementary reactions, overall rxn
Rate determining step approximation
Know how to derive the rate law
when step(1) is slow step, when step(2) is slow step
Catalyst (lowers the activation energy for forward AND reverse rxn)
Intermediate
Inhibitor (does NOT increase the activation energy
CH 14 : CHEMICAL EQUILIBRIUM
Write the equilibrium constants Kc and Kp and the reaction quotients Q for a homogeneous and a heterogeneous
reaction
Calculate the equilibrium constant for a reaction when the equilibrium constant for the reverse rxn
or a multiple of the reaction is given
Write the equilibrium constants for the overall rxn of a mechanism when the equilibrium constants for
the elementary steps are given (and related problems)
Find Kp when Kc is given an vice versa
Determine in which direction a rxn will proceed when concentrations (pressures) are given and K c (Kp ) is
Given
There will be calculations – bring your scientific calculator
Show all your calculations
Show your calculations with units
Do not round until you report an answer
If the answer is used in a subsequent calculation do NOT use the rounded answer
Report the answers with correct units and correct sig. fig.
No units are wrong units
Partial credit only when all work (with units) is shown
No credit for a bare answer to a numerical problem (when calculations are needed)
The exam will be a 100 minute exam
Because of the time constraint I cannot promise that all subjects listed above will be on the exam
Do all assigned end of chapter problems
One or more end of chapter problems may be on the exam
Study the Practice Exercises and the Daily Quizzes
Cheat Sheet:
One letter size sheet (front and back), no copies from a book taped or stapled
No solutions for end of chapter problems on the cheat sheet
Only handwritten entries
Your name must be printed on the sheet.
The sheet must be handed in with the exam.