7. 13.74 The following data were collected for the reaction between hydrogen and nitric oxide at 700°C: 2H₂(g) + 2NO(g) →→2H₂O(g) + N₂(g) Experiment 1 2 3 [H₂] 0.010 0.0050 0.010 [NO] 0.025 0.025 0.0125 Initial Rate (M/s) 2.4 x 10-6 1.2 x 10-6 0.60 × 10-6 (a) Determine the order of the reaction. (b) Calcu- late the rate constant. (c) Suggest a plausible mech- anism that is consistent with the rate law. (Hint: Assume that the oxygen atom is the intermediate.)

(5) IV. Hydrogen and carbon monoxide react to give formaldehyde under certain conditions. H2(g) + CO(g) = HCHO(g) The mechanism proposed for this reaction is H2(g) = 2 H(g) H(g) + CO(g) H(g),+ HCO(g) → HCHO What rate law is derived from this mechanism? Step 1 Step 2 Step 3 fast HCO(g) slow > fast

Consider the gas-phase reaction of nitric oxide with hydrogen at 1280°C 2NO(g) + 2H2(g) →N2(g) + 2H20(g) Experiment [NO](M) 5.00 x 10-3 1.00 x 10-2 1.00 x 10-2 [H2](M) 2.00 x 10-3 2.00 x 10-3 4.00 x 10-3 Initial Rate (M/s) 1.25 x 10-5 5.00 x 10-5 1.00 x 104 Determine the a. the rate law b. overall reaction order C. the rate constant, k. 123

1. HBr +O2 →HOOBF 2(g) (slow) 2. НООBr + HBr, (8) 2HOB" 2g) (fast) 3. 2{НОBr + HBr, T →H,O« +Br} (fast) (8) (g) 2(g) 4HB +0,→2H,O, +2Br%e - (3) Consider the above reaction mechanism. The rate-law equation from this reaction would be - K[HOB1]*[HBr] K[HBr]*[O,] = k[HOB1]² r = k[HBr]'[O,]' а. r = d. = b. e. impossible to tell from this information r = с.

(ii) At elevated temperatures, nitrogen dioxide decomposes to nitric oxide and molecular oxygen: 2NO2(g) – → 2NO(g) + O2(g) The change in concentration of NO2 with time at 300 °C is given below: t (s) 100 200 300 400 500 [NO2]/103 (mol dm-3) 8.0 5.6 4.3 3.5 2.9 2.5 By appropriate plotting of the data and use of this graph: (a) verify that this reaction is second order with respect to NO2; (b) determine the rate constant for this reaction.

HWK3/7 (a) Consider the combustion of ammonia, given below: 4 NH3(g) + 5 O2(g)  4 NO(g) + 6 H2O(g) If NH3(g) is decreasing at the rate of 0.440 mol/s, what are the rates of change of O2(g), NO(g), and H2O(g)? O2(g)/t = ______ mol/s NO(g)/t = _____ mol/s H2O(g)/t =______  mol/s (b) The decomposition reaction given below: 2 NOCl(g)  2 NO(g) + 1 Cl2(g) is carried out in a closed reaction vessel. If the partial pressure of NOCl(g) is decreasing at the rate of 555 torr/min, what is the rate of change of the total pressure in the vessel? Ptot /t = ______ torr/min

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Activated complex 400 (b) 300 Products Potential Energy (a) 200 (c) 100 Reactants Reaction Pathway Activated complex 400 (b) 300 Products Potential Energy (a) 200 (c) 100 Reactants Reaction Pathway Alex thinks that the graph above represents an exothermic reaction and the AH = +400kJ and energy will be released in this reaction. Is Alex correct? If not, find his error and then correct it with explanation. %3D

6:00 pm Remaining Time: 01:15:20 Calcium chloride, CaCl2 and sodium phosphate, Na3PO4 react as follows. 3 CaCl2(aq) + 2 Na3PO4(aq) → Ca3(PO4)2(s) + 6 Nacl(aq) Molar Masses CaCl2 NazPO4 Ca3(PO4)2 NaCl (in g mol-1) 110.98 141.96 310.18 58.44 The reaction results in a 79.2% yield for the production of Ca3(PO4)2. If excess Na3PO4 is used, what mass of CaCl2 would be required to produce 14.1 g of Ca3(PO4)2? 12.0 g 2.12 g O 6.37 g 15.6 g 19.1 g Question Menu - Naxt Вack Quit & Save Submit Assignment MacBook Air F12 DD DII F11 F10 F9 F8 F7 F6 ( ) & 7

16.28 Phosgene is a toxic gas prepared by the reaction of carbon monoxide with chlorine: CO(g) + Cl,(g) COC»(g) These data were obtained in a kinetics study of its formation: Initial [CO] (mol/L) Initial [Cl,] (mol/L) Initial Rate Experiment (mol/L•s) 1.29×10–29 1.33×10-30 1.30X10–29 1.32×10-31 1 1.00 0.100 0.100 0.100 0.100 3 1.00 4 0.100 0.0100 (a) Write the rate law for the formation of phosgene. (b) Calculate the average value of the rate constant.