3 For the reaction below, initially 3.5 mol of NH¸ are placed in a 4.0 L reaction chamber. After 3.0 minutes only 1.6 moles of NH, remain. SHOW ALL YOUR WORK. Rates should be in M/s 4 NH₂(g) + 5 O₂(g) → 4 NO(g) + 6 H₂O(g) a. Calculate the average rate of reaction with respect to NH,. b. Calculate the average rate at which H₂O is being formed. c. Calculate the average rate at which O, is being consumed.

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?

For the reaction of crystal violet with NaOH(aq), the measured rate of reaction is 1.27 106 mol L1 s1 when the concentration of crystal violet cation is 4.13 105 mol/L. (a) Estimate how long it will take for the concentration of crystal violet to drop from 4.30 105 mol/L to 3.96 105 mol/L. (b) Could you use the same method to make an accurate estimate of how long it would take for the concentration of crystal violet to drop from 4.30 105 mol/L to 0.43 105 mol/L? Explain why or why not.

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?