For the reaction 2 N2O5(g) → 4 NO2(g) + O2(g), the following mechanism has been proposed: N2O5 →> NO₂+ NO3_(K1) NO2 + NO3 → N2O5 (k-1) NO2 + NO3 → → NO2 + O2 + NO (K2) NO + N2O5- NO2 + NO2 + NO2 (K3) d[N₂O5] __2k‚k₂[N2O5] Indicate whether the following rate expression is acceptable: dt k₁₁+ k₂

The reaction NO(g) + O,(g) — NO,(g) + 0(g) plays a role in the formation of nitrogen dioxide in automobile engines. Suppose that a series of experiments measured the rate of this reaction at 500 K and produced the following data; [NO] (mol L ’) [OJ (mol L 1) Rate = -A[NO]/Af (mol L_1 s-1) 0.002 0.005 8.0 X 10"'7 0.002 0.010 1.6 X 10-'6 0.006 0.005 2.4 X IO-'6 Derive a rate law for the reaction and determine the value of the rate constant.

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?

One mechanism for the destruction of ozone in the upper atmosphere is a. Which species is a catalyst? b. Which species is an intermediate? c. Ea for the uncatalyzed reaction O3(g)+O(g)2O2(g) is 14.0 kJ. Ea. for the same reaction when catalyzed is 11.9 kJ. What is the ratio of the rate constant for the catalyzed reaction to that for the uncatalyzed reaction at 25C? Assume that the frequency factor A is the same for each reaction.

Substances that poison a catalyst pose a major concern for many engineering designs, including those for catalytic converters. One design option is to add materials that react with potential poisons before they reach the catalyst. Among the commonly encountered catalyst poisons are silicon and phosphorus, which typically form phosphate or silicate ions in the oxidizing environment of an engine. Group 2 elements are added to the catalyst to react with these contaminants before they reach the working portion of the catalytic converter. If estimates show that a catalytic converter will be exposed to 625 g of silicon during its lifetime, what mass of beryllium would need to be included in the design?

The reaction H2SeO3(aq) + 6I-(aq) + 4H+(aq) Se(s) + 2I-3(aq) + 3H2O(l) was studied at 0C, and the following data were obtained: [H2SeO3]0 (mol/L) [H+]0 (mol/L) [I]0(mol/L) Initial Rate (mol/L s) 1.0 104 2.0 102 2.0 102 1.66 107 2.0 104 2.0 102 2.0 10-2 3.33 107 3.0 104 2.0 102 2.0 102 4.99 107 1.0 104 4.0 102 2.0 102 6.66 107 1.0 104 1.0 102 2.0 102 0.42 107 1.0 104 2.0 102 4.0 102 13.2 107 1.0 104 1.0 102 4.0 102 3.36 107 These relationships hold only if there is a very small amount of I3 present. What is the rate law and the value of the rate constant? (Assumethatrate=[H2SeO3]t)

The label on a bottle of 3% (by volume) hydrogen peroxide, H2O2, purchased at a grocery store, states that the solution should be stored in a cool, dark place. H2O2decomposes slowly over time, and the rate of decomposition increases with an increase in temperature and in the presence of light. However, the rate of decomposition increases dramatically if a small amount of powdered MnO- is added to the solution. The decomposition products are H2O and O2. MnO2 is not consumed in the reaction. Write the equation for the decomposition of H2O2. What role does MnO2 play? In the chemistry lab, a student substituted a chunk of MnO2 for the powdered compound. The reaction rate was not appreciably increased. WTiat is one possible explanation for this observation? Is MnO2 part of the stoichiometry of the decomposition of H2O2?

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.

For a first order gas phase reaction A products, k = 7.2 104s1 at 660. K and k = 1.7 102s1 at 720. K. If the initial pressure of A is 536 torr at 295C, how long will it take for the pressure of A to decrease to 268 torr?

The acid-catalyzed iodination of acetone CH3COCH3(aq) + I2(aq) CH3COCH2I(aq) + HI(aq) is a common laboratory experiment used in general chemistry courses to teach the method of initial rates. The reaction is followed spectrophotometrically by the disappearance of the color of iodine in the solution. The following data (J. P. Birk and D. L Walters, Journal of Chemical Education, Vol. 69, p. 585, 1992) were collected at 23 C for this reaction. Determine the rate law for this reaction.