a . A confined space has a gas-phase benzene concentration of 0.8 ppmv, just below the OSHA permissible exposure limit. What mass of benzene is present in a water droplet present in this confined space? Assume the water droplet is 0.150 mL in volume and has achieved equilibrium with the gas phase. The Henry's Law constant for benzene, Hm, is 4.31x10-3 atm.m3/mol. (This value is reported in Appendix A-2 in your textbook.)