Reaction Rates
For the reaction A + 3B -> 2C, How does the rate of disappearance of B compare to the rate of production of C?
The rate of disappearance of B is 3/2 the rate of appearance of C
Write the predicted rate law for the reaction
1A + 2B + 1C -> 2D + 1E
rate = k[A][B]2[C]
Write the overall reaction for the following mechanism:
Step 1: H2O2 + I- -> H2O + OI-
Step 2: H2O2 + OI- -> H2O + O2 + I-
2 H2O2 -> 2 H2O + O2
What percentage of material will persist after 60 minutes if it's half life is 30 minutes?
25%
The order wrt a reactant whose change in concentration has no effect
zero order
For the reaction 2A + 3B -> 4C + 5D the rate of the reaction in terms of C would be written as
+ 1/4
For the rate law Rate = k[A][B]2
The overall order for this reaction is _____
3rd order
What is the intermediate in the following mechanism?
Step 1: H2O2 + I- -> H2O + OI-
Step 2: H2O2 + OI- -> H2O + O2 + I-
OI-
The energy needed for a reaction to proceed from reactants to products is called
Activation Energy
heat goes from system to surroundings
exothermic
In the combustion of methane,
CH4 + 2 O2 -> CO2 + 2 H2O
Which reactant has the greatest rate of disappearance?
O2
Rate = k[CHCl3]2[Cl]
If the concentration of CHCl3 doubles while the concentration of Cl2 is kept the same, the rate will
Quadruple
Write the rate law
Step 1: H2O2 + I- -> H2O + OI- (slow)
Step 2: H2O2 + OI- -> H2O + O2 + I- (fast)
rate = k[H2O2][I-]
True or False:
Catalysts do not alter the mechanism of the reaction and never appear in the rate law
False
this is lowered with a catalyst
N2 + O2 -> 2NO
If the initial concentration of N2 was 0.500 M and the concentration of N2 was 0.450 M after 0.100 s, what is the rate of reaction?
0.500 M/s
A reaction is first order in A. If the rate constant of the reaction is 6.00 x 10-3 s-1, What is the half life of the reaction?
115 s
What is the catalyst for the reaction?
Step 1: H2O2 + I- -> H2O + OI-
Step 2: H2O2 + OI- -> H2O + O2 + I-
I-
Collision theory assumes that the rate of reaction depends on _________ and ___________.
The energy of collisions and the orientation of colliding molecules
two requirements for successful collision
enough energy
correct orientation
If the rate of formation of ammonia is 0.345 M/s, What is the rate of disappearance of H2?
Nitrogen gas reacts with Hydrogen gas to create Ammonia.
N2 + 3 H2 -> 2 NH3
0.518 M/s
The first order reaction has k = 8.00 s-1. If [A]0 = 0.500 M, how long will it take to make [A] = 0.200 M?
0.115 s
What is the molecularity of the rate determining step?
Step 1: H2O2 + I- -> H2O + OI-
Step 2: H2O2 + OI- -> H2O + O2 + I-
Bimolecular
True or False:
The mechanism, rate law, and activation energy all change when a catalyst is added.
True
another name for transition state
activated complex