The lifetime of OH is determined by its reaction with trace gases in the atmosphere. The most abundant trace gases that react with OH via second order reactions are CH4 and CO. Given that k(CH4) = 10-14.19 cm3 molecule-1 s-1 and k(CO) = 10-12.82 cm3 molecule-1 s-1, please determine the lifetime of the OH radical (in seconds) with respect to these two reactions. Assume a pressure of 1 atm and a temperature of 25 C. Assume tropospheric concentrations of CH4 and CO are 1.69 ppm and 108.6 ppb, respectively. (Hint: Take the CO and CH4 concentrations to be constant and absorb those into the rate constants. For example: k(CH4) * [OH] * [CH4] = k'(CH4) * [OH].)