Equilibrium Rate 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 Return

 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.  Return Return

 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 Return

 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? 2NH 3  N 2 + 3H 2 H2H2 Return

 For the reaction, 2XO + O 2  2XO 2, the following data was obtained. What is the rate law for the reaction? Trial [XO] [O2] rate  Rate = k [XO] 2 [O 2 ] 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 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] Return

 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 Return

 The reaction A +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  Return Return

 The decomposition of H 2 O 2 is determined to occur by the following mechanism: H 2 O 2 + I -  H 2 O + IO - (slow) H 2 O 2 + IO -  H 2 O + O 2 + I - (fast) What is the overall reaction?  2H 2 O 2  H 2 O + O 2  Return Return

 How does a catalyst alter the rate of a chemical reaction?  Lowers the activation energy (provides an alternative pathway) Return

 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  Return Return

 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 Return

 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 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 Return

 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?  2 nd order  Return Return

 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  Return Return

 In a first order reaction, what fraction of the material will remain after 4 half lives?  1/16 Return

 A first order reaction has a rate constant of min -1. What is the half life of the reaction?  21.8 minutes  Return Return

 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 Return

 How does changing the concentration affect the rate constant?  It has no affect  Return Return

 How does increasing the temperature affect the rate and the rate constant?  It increases both the rate constant and the rate Return

 What is the unit for the rate constant in a reaction that is 2 nd order overall?  L/mol s  Return Return

 In a zero order rate law, what units must the rate concept possess?  Mol/L time  Return Return

 A rate constant has the units s -1. Doubling the concentration would have what affect on the overall rate of reaction? It would double the rate Return

 What factors affect the value of Keq?  Temperature and nature of reactants  Return Return

 How does a catalyst affect the value of Keq?  It has no effect Return

 If K>1, what does that indicate about the equilibrium position?  The concentration of products is greater than the concentration of reactants at equilibrium  Return Return

 Increasing the temperature increases the value of Keq. Is the reaction endothermic or endothermic?  endothermic Return

 According to the equation: 3H 2 (g) + N 2 (g)  2NH 3 (g), if the volume of the reaction chamber increases, will the forward or reverse reaction be favored?  Reverse reaction Return