Definition
The change of the concentration/ the change in time
average reaction rate
the starting point of a reaction
reactants
cutting down reactants into smaller pieces
increasing surface area
the rate law is = product of the specific rate constant and _________
concentration of reactant/s
A + B = C
a reaction has an overall order 5
If the reaction order for the B = 1 what is the reaction order for A?
4
Indicate the order of reaction consistent with this observation:
A plot of the concentration of the reactant versus time yields a straight line.
Zero order because [A] over time is zero order.
unstable compound formed when reactants change to products
activated complex
the top of the energy diagram
activated complex
Which factor is adjusted to increase number of collisions between particles
temperature
True or False
The value of K is different from one reaction to another
True
C + D = W
If this reaction has the following rate law
Rate = K[D]
What does that mean for c ?
the reaction order in C = Zero
Indicate the order of reaction consistent with this observation:
The reaction has a half-life that is independent of initial concentration.
First order because t1/2 = 0.693/k
The integrated rate law.
What is it gives the rate of a chemical reaction as a function of the initial concentration of one or more reactants after a specific period of time.
the distance between reactants and activated complex
activation energy Ea
a factor that decrease the amount of activation energy required for reactions to occur
catalyst
When determining the rate of a chemical reaction, the reactants have this sign. (positive or negative)?
What is Reactants have a negative sign?
A reaction has the following rate law
Rate = K[C] [D]2
What will happen to the rate when the concentration of D is doubled?
the rate law will become fourfold ( 4*rate)
This reaction was monitored as a function of time:
A --> B + C
A plot of ln[A] versus time yields a straight line with slope -0.0045/s
What is the value of the rate constant (k) for this reaction at this temperature and what is the rate law?
4.5 x 10-3 s-1
Rate = k[A] or Rate = 4.5 x 10-3 s-1[A]
R = K [A]m[B]n
we call m+n this.
What is Reaction order?
When the reactants have higher energy than products
energy is released / exothermic reaction
What makes lithium to react faster than sodium in water
nature of reactants ( Li is above Na in the activity series)
This species has the greatest rate of disappearance in the reaction below?
CH₄ + 2 O₂ → 2 CO₂ + H₂O
What is O2?
The reactants are CH₄ and O₂, so it can only be one of those. Twice as many O₂ molecules react as CH₄.
A reaction in which A, B, and C react to form products is first order in A, second order in B, and zero order in C.
Write a rate law for the reaction.
Rate = k[A][B]2
The decomposition of SO2Cl2 is first order in SO2Cl2 and has a rate constant of 1.42 x 10-4 s-1 at a certain temperature.
What is the half-life for this reaction?
First Order: t1/2 = 0.693/k
k = 1.42 x 10-4 s-1
t1/2 = 4880 seconds
the units for the rate constant for a zero order reaction
What is M･s⁻¹ or M/s ?
the minimum amount of energy required to start the reaction
activation energy
The reaction A + 2 B → C has the rate law:
Rate = k[A][B]
This is the factor of the rate of reaction increase when both [A] and [B] are doubled.
What is 4?
[2]x[2] = 4
For the chemical reaction:
A + 2B → C
If slope of [B] vs. time is -0.200 M/s, This is rate of reaction?
Rate = -1/2 Δ[B]/Δt
Δ[B]/Δt = -0.200 M/s
-0.200 M/s * -½ = 0.100 M/s
Rate = 0.100 M/s
The table data was collected for this reaction:
2 NO2(g) + F2(g) --> 2 NO2F(g)
[NO2] (M) [F2] (M) Initial Rate (M/s)
0.100 0.100 0.026
0.200 0.100 0.051
0.200 0.200 0.103
0.400 0.400 0.411
Write an expression for the reaction rate law and calculate the value of the rate constant, k
rate = k[NO2][F2]
k = 2.57 M-1 s-1
The half-life for the radioactive decay of U-238 is 4.5 billion (4.5 x 109) years and is independent of initial concentration.
How long it will take for 10% of the U-238 atoms in a sample of U-238 to decay.
It is first order.
t1/2 = 4.5 x 109
t1/2 = 0.693/k
k = 1.54 x 10-10
[A]t = 0.90[A]0
ln([A]t/[A]0) = -kt → ln(0.90[A]0/[A]0) = -(1.54 x 10-10)t
ln(0.90) = -1.54 x 10-10t
t = 6.8 x 108 years