Calculate the rate constant at 500 K for the second-order gas-phase reaction between Cl and H2 given the frequency factor, A = 8.1 × 10−10 dm3 mol−1 s−1 and activation energy Ea = 23 kJ mol–1.

Cosmetics have often antimicrobial agents, such as methyl paraben, to prevent growth of mold and bacteria. Suppose the antimicrobial agent in a tube of sunscreen degrades with first-order kinetics, with a rate constant of 2.31 x 10-4 hr¬ at 25°C. A) Calculate the half-life of the antimicrobial agent at 25°C. Be sure to include the units. B) The activation energy for the degradation reaction is 9.2 kJ mol-1. Sup- pose you store your sunscreen in the locker room at the gym, which has an average temperature of 35°C. What is the half-life of the an- timicrobial agent in the conditions at the gym?

For the gas phase isomerization of methyl cis-cinnamate, cis-C6H5 CH=CHCOOCH3 → trans-C6H5 CH=CHCOOCH3 the rate constant in s¹ has been determined at several temperatures. When In k is plotted against the reciprocal of the Kelvin temperature, the resulting linear plot has a slope of −2.09 × 10¹ K and a y-intercept of 24.3. The value of the rate constant for the gas phase isomerization of methyl cis-cinnamate at 667 K is S-¹. (Enter your answer to one significant figure.)

Under certain conditions, the reaction 3 A+ 4B 5C is observed to proceed at a rate of 0.0275 M s ¹. What is the corresponding rate of change in product C?