4. Cyclobutane decomposes to ethylene according to the equation: C4H8(g) →2C2H4(g). Determine the order of the reaction and rate constant based on the following pressures, which were recorded when the reaction was carried out at 430°C in a constant-volume vessel. Time, s PC4H8 (mm Hg) In P 0 400 2000 316 4000 248 6000 196 8000 155 10000 122

The hydrolysis of the sugar sucrose to the sugars glucose and fructose, C12H22O11+H2OC6H12O6+C6H12O6 follows a first-order rate equation for the disappearance of sucrose: Rate =k[C12H22O11] (The products of the reaction, glucose and fructose, have the same molecular formulas but differ in the arrangement of the atoms in their molecules.) (a) In neutral solution, k=2.11011s1 at 27 C and 8.51011s1 at 37 C. Determine the activation energy, the frequency factor, and the rate constant for this equation at 47 C (assuming the kinetics remain consistent with the Arrhenius equation at this temperature). (b) When a solution of sucrose with an initial concentration of 0.150 M reaches equilibrium, the concentration of sucrose is 1.65107M . How long will it take the solution to reach equilibrium at 27 C in the absence of a catalyst? Because the concentration of sucrose at equilibrium is so low, assume that the reaction is irreversible. (c) Why does assuming that the reaction is irreversible simplify the calculation in pan (b)?

The rate of the reaction O(g)+NO2(g)NO(g)+O2(g) was studied at a certain temperature. a. In one experiment, NO2 was in large excess, at a concentration of 1.0 1013 molecules/cm3 with the following data collected: Time(s) [O](atoms/cm3) 0 5.0 109 1.0 102 1.9 109 2.0 102 6.8 108 3.0 102 2.5 108 What is the order of the reaction with respect to oxygen atoms? b. The reaction is known to be first order with respect to NO2 Determine the overall rate law and the value of the rate constant.

A drug decomposes in the blood by a first-order process. A pill containing 0.500 g of the active ingredient reaches its maximum concentration of 2.5 mg/ 100 mL of blood. If the half-life of the active ingredient is 75 min, what is its concentration in the blood 2.0 h after the maximum concentration has been reached?