Polyatomic Ions, Chem 162 Final,
CHEM162 exam 2 Questions and Verified
Answers
integrated rate laws
math expression describing change in concentration of a reactant with time, trying to achieve
a linear graph
zero order reaction (integrated rate law)
[A]subt = -kt + [A]sub0
[A] vs time negative linear
graph units of k are M/time
first order reaction (integrated rate law)
ln[A]subt = -kt + ln[A]sub0
ln[A] vs time negative linear graph
units of k are 1/time
second order reaction (integrated rate law)
1/[A]subt = kt + 1/[A]sub0
1/[A] vs time positive linear graph
units of k are 1/M*time
half lives
, tsub1/2--> the time in the course of a chemical reaction during which the concentration of
a reactant decreases by half
zero order half life
[A]subk
first order half life
0.693/k (ln2/k)
second order half life
1 / k[A]sub0
pseudo rate law
describes a reaction in which all the reactants but one are present at such high concentrations
that they do not decrease significantly during the reaction; the reaction rate is controlled by the
concentration of the limiting reactant
A+B-->C+D
Rate = k'[B]^b
k' = k[A]^a
Overall order = a + b
collision theory
before atoms, molecules, or ions an react, they must first collide. an effective collision between
2 molecules has enough energy to break key bonds. the activation energy (Esuba) is the
minimum energy that must be supplied by collisions for a reaction to occur. The orientations of
the colliding species also affect the reaction rate (LOOK AT GRAPHS)
Arrhenius equation
k=Ae^(-Ea/RT)
R is universal gas constant
CHEM162 exam 2 Questions and Verified
Answers
integrated rate laws
math expression describing change in concentration of a reactant with time, trying to achieve
a linear graph
zero order reaction (integrated rate law)
[A]subt = -kt + [A]sub0
[A] vs time negative linear
graph units of k are M/time
first order reaction (integrated rate law)
ln[A]subt = -kt + ln[A]sub0
ln[A] vs time negative linear graph
units of k are 1/time
second order reaction (integrated rate law)
1/[A]subt = kt + 1/[A]sub0
1/[A] vs time positive linear graph
units of k are 1/M*time
half lives
, tsub1/2--> the time in the course of a chemical reaction during which the concentration of
a reactant decreases by half
zero order half life
[A]subk
first order half life
0.693/k (ln2/k)
second order half life
1 / k[A]sub0
pseudo rate law
describes a reaction in which all the reactants but one are present at such high concentrations
that they do not decrease significantly during the reaction; the reaction rate is controlled by the
concentration of the limiting reactant
A+B-->C+D
Rate = k'[B]^b
k' = k[A]^a
Overall order = a + b
collision theory
before atoms, molecules, or ions an react, they must first collide. an effective collision between
2 molecules has enough energy to break key bonds. the activation energy (Esuba) is the
minimum energy that must be supplied by collisions for a reaction to occur. The orientations of
the colliding species also affect the reaction rate (LOOK AT GRAPHS)
Arrhenius equation
k=Ae^(-Ea/RT)
R is universal gas constant
