The table shows the variation of the rate constant with temperature for the first-order reaction. → 2N2O(g) 2N2O4(g) + O2(g) Determine graphically the activation energy for the reaction. Be sure your answer has the correct number of significant digits. T(K) k (우) 310. 1.57 10 320. 5.95 x 10 -4 330. 2.27 10 -4 340. 6.83 x 10 -3 350. 2.16 × 10 Note: Reference the Fundamental constants table for additional information. kJ mol Π

The decomposition of ozone is a second-order reaction with a rate constant of 30.6 atm1 s1 at 95 C. 2O3(g)3O2(g) If ozone is originally present at a partial pressure of 21 torr, calculate the length of time needed for the ozone pressure to decrease to 1.0 torr.

The Raschig reaction produces the industrially important reducing agent hydrazine, N2H4, from ammonia, NH3, and hypochlorite ion, OCl−, in basic aqueous solution. A proposed mechanism is Step 1: Step 2: Step 3: What is the overall stoichiometric equation? Which step is rate-limiting? What reaction intermediates are involved? What rate law is predicted by this mechanism?

At 620. K butadiene dimerizes at a moderate rate. The following data were obtained in an experiment involving this reaction: t(s) [C4H6] (mol/L) 0 0.01000 1000.. 0.00629 2000. 0.00459 3000. 0.00361 a. Determine the order of the reaction in butadiene. b. In how many seconds is the dimerization 1.0% complete? c. In how many seconds is the dimerization 10.0% complete? d. What is the half-life for the reaction if the initial concentration of butadiene is 0.0200 M? e. Use the results from this problem and Exercise 45 to calculate the activation energy for the dimerization of butadiene.

The initial concentration of the reactant in a tirst-order reaction A —» products is 0.64 rnol/L and the half-life is 30.0 s. Calculate the concentration of the reactant exactly 60 s after initiation of the reaction. How long would it take for the concentration of the reactant to drop to one-eighth its initial value? How long would it take for the concentration of the reactant to drop to 0.040 mol/L?

The following statements relate to the reaction for the formation of HI: H2(g) + I2(g) -* 2 HI(g) Rate = it[HJ [I2J Determine which of the following statements are true. If a statement is false, indicate why it is incorrect. The reaction must occur in a single step. This is a second-order reaction overall. Raising the temperature will cause the value of k to decrease. Raising the temperature lowers the activation energy' for this reaction. If the concentrations of both reactants are doubled, the rate will double. Adding a catalyst in the reaction will cause the initial rate to increase.

You are studying the kinetics of the reaction H2(g) + F2(g) 2HF(g) and you wish to determine a mechanism for the reaction. You run the reaction twice by keeping one reactant at a much higher pressure than the other reactant (this lower-pressure reactant begins at 1.000 atm). Unfortunately, you neglect to record which reactant was at the higher pressure, and you forget which it was later. Your data for the first experiment are: Pressure of HF (atm) Time(min) 0 0 0.300 30.0 0.600 65.8 0.900 110.4 1.200 169.1 1.500 255.9 When you ran the second experiment (in which the higher pressure reactant was run at a much higher pressure), you determine the values of the apparent rate constants to be the same. It also turns out that you find data taken from another person in the lab. This individual found that the reaction proceeds 40.0 times faster at 55C than at 35C. You also know, from the energy-level diagram, that there are three steps to the mechanism, and the first step has the highest activation energy. You look up the bond energies of the species involved and they are (in kJ/mol): H8H (432), F8F (154), and H8F (565). a. Sketch an energy-level diagram (qualitative) that is consistent with the one described previously. Hint: See Exercise 106. b. Develop a reasonable mechanism for the reaction. c. Which reactant was limiting in the experiments?

Isomerization of CH3NC occurs slowly when CH3NC is heated. CH3NC(g) CH3CN(g) To study the rate of this reaction at 488 K, data on [CH3NC] were collected at various times. Analysis led to the following graph. (a) What is the rate law for this reaction? (b) What is the equation for the straight line in this graph? (c) Calculate the rate constant for this reaction. (d) How long does it take for half of the sample to isomerize? (e) What is the concentration of CH3NC after 1.0 104 s?

Many biochemical reactions are catalyzed by acids. A typical mechanism consistent with the experimental results (in which HA is the acid and X is the reactant) is Step 1: Step 2: Step 3: Derive the rate law from this mechanism. Determine the order of reaction with respect to HA. Determine how doubling the concentration of HA would affect the rate of the reaction.

In Exercise 11.39, if the initial concentration of N2Oj is 0.100 .\1. how long will it take for the concentration to drop to 0.0100 times its original value? The decomposition of N2O5 in solution in carbon tetrachloride is a first-order reaction: 2N2O5—»4NO2 + O2 The rate constant at a given temperature is found to be 5.25 X 10-4 s-’. If the initial concentration of N2O5 is 0.200 M, what is its concentration after exactly 10 minutes have passed?