19.A first-order reaction has a rate constant of 7.5 ×10-3/s. The time required for the reaction to be 60% complete is A.3.8 ×10-3s.B.6.9 ×10-3s.C.120 s.D.130 s.E.68 s.5
20.The thermal decomposition of acetaldehyde, CH3CHO →CH4+ CO, is a second-order reaction. The following data were obtained at 518°C.Based on the data given, what is the half-life for the disappearance of acetaldehyde? 21.The reaction 2NO2(g) →2NO(g) + O2(g) is suspected to be second order in NO2. Which of the following kinetic plots would be the most useful to confirm whether or not the reaction is second order? 22.Nitric oxide reacts with chlorine to form nitrosyl chloride, NOCl. Use the following data to determine the rate equation for the reaction.NO + (1/2)Cl2→NOCl23.The activation energy for the reaction CH3CO →CH3+ CO is 71 kJ/mol. How many times greater is the rate constant for this reaction at 170°C than at 150°C? A. 1.1B. 5.0C. 4.0D. 0.40E.2.56
24.The reaction A + 2B →productshas been found to have the rate law, rate = k[A] [B]2. While holding the concentration of A constant, the concentration of B is increased from xto 3x. Predict by what factor the rate of reaction increases. 25.When acetaldehyde at a pressure of 364 mmHg is introduced into an evacuated 500. mL flask at 518°C, the half-life for the second-order decomposition process, CH3CHO →CH4+ CO, is 410. s. What will the total pressure in the flask be after 1.00 hour? 26.For the hypothetical reaction A + 3B →2C, the rate of appearance of C given by (∆[C]/∆t) may also be expressed as 27.The isomerization of cyclopropane to form propeneis a first-order reaction. At 760 K, 15% of a sample of cyclopropane changes to propene in 6.8 min. What is the half-life of cyclopropane at 760 K? A.29 min B.2.5 min C.230 min D.3.4 ×10-2min E.23 min 7
28.The isomerization of cyclopropane follows first order kinetics. The rate constant at 700 K is 6.20 ×10-4 min-1, and the half-life at 760 K is 29.0 min. Calculate the activation energy for this reaction.