500 400 300 200 100 Equilibrium Rate Constant Integrated Rate Law Activation Energy Reaction...
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EquilibriumRate Constant
Integrated Rate Law
Activation Energy
Reaction Mechanisms
Rate Laws
A reaction has the rate law,Rate = k[A][B]2. What is the
overall order for the reaction?
Third Order Overall
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A reaction has the rate law, rate = k[A][B]2. If the
concentration of both A and B are doubled, what happens to the rate?
Increases by a factor of 8.
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The equation, 2A + 2B C + D, describes an elementary reaction which takes place in a single step. What is the rate law?
Rate = k[A]2[B]2
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Based on the following equation, which of the following compounds would you expect to undergo the most change in concentration in a given amount of time?
2NH3 N2 + 3H2
H2
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For the reaction, 2XO + O2 2XO2, the following data was obtained. What is the rate law for the reaction?
Trial [XO] [O2] rate 1 0.010 0.010 2.5 2 0.010 0.020 5.0 3 0.030 0.020 45.0
Rate = k [XO]2[O2]Return
The reaction: A + 3B D + F was studied and the following mechanism was determined
A + B ↔ C (fast) C + B D + E (slow) E + B F (very fast)Which step is the rate determining step?
The second step (slow step) Return
Suppose the reaction:
A + B D followed the mechanism
A + B ↔ C (fast)C D (slow)What is the rate law
for the reaction?
Rate = k[A][B]
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The reaction A + 3B D + F was followed and the following mechanism was determined:
A + B ↔ C (fast) C + B D + E (slow) E + B F (very fast)Identify the intermediates.
C and E
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The reactionA +3B D + F was
studied and the mechanism was determined to be:
A + B ↔ C (fast)C + B D + E (slow)E + B F (very fast)What is the rate law?
Rate = k[A][B]2
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The decomposition of H2O2 is determined to occur by the following mechanism:
H2O2 + I- H2O + IO- (slow)H2O2 + IO- H2O + O2 + I- (fast)What is the overall reaction? 2H2O2 H2O + O2
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How does a catalyst alter the rate of a chemical reaction?
Lowers the activation energy (provides an alternative pathway)
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For a one step reaction, the activation energy for the forward reaction is 40 kJ/mol and the enthalpy of reaction is -20 kJ/mole. Which reaction is slower; the forward or the reverse?
The reverse reaction is slower
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According to the collision theory, what two conditions must be met in order for a reaction to occur?
Reactants must possess a minimum amount of energy and the collisions must occur with the correct orientation
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How can the slope of a plot of ln(k) vs 1/T for a reaction be used to determine the activation energy?
By multiplying by –R (-8.314) Return
For a one step reaction the activation energy is 40 kJ/mol and the enthalpy of reaction is 20 kJ/mol. What is the activation energy of the reverse reaction?
20 kJ/mol
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The following reaction was studied: A B + C. The graph of 1/[A] vs time gave a straight line. What is the order of the reaction with respect to A?
2nd order
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Given a reaction, 2A + B P, for which the observed rate law is rate = k [A], what is the integrated rate law?
ln[A] = -kt + ln[A]o
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In a first order reaction, what fraction of the material will remain after 4 half lives?
1/16
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A first order reaction has a rate constant of 0.00318 min-1. What is the half life of the reaction?
21.8 minutes
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A graph of [A] vs time gave a straight line. How does doubling the concentration of A affect the rate of the reaction?
It has no affect
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How does changing the concentration affect the rate constant?
It has no affect
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How does increasing the temperature affect the rate and the rate constant?
It increases both the rate constant and the rate
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What is the unit for the rate constant in a reaction that is 2nd order overall?
L/mol s
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In a zero order rate law, what units must the rate concept possess?
Mol/L time Return
A rate constanthas the units s-1.
Doubling the concentration would have what affect on the overall rate of reaction?
It would double the rate
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What factors affect the value of Keq?
Temperature and nature of reactants
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How does a catalyst affect the value of Keq?
It has no effect
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If K>1, what does that indicate about the equilibrium position?
The concentration of products is greater than the concentration of reactants at equilibrium
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Increasing the temperature increases the value of Keq. Is the reaction endothermic or endothermic?
endothermic
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According to the equation:3H2(g) + N2(g) 2NH3(g),
if the volume of the reaction chamber increases, will the forward or reverse reaction be favored?
Reverse reactionReturn