Pressure: 760 mmHg = 1 atm, 760 mmHg=101,325 Pa, 1000 Pa=1 kPa Other: 1000 ppm = 1 ppb K = C + 273.15 2. Convert a 1 mg/m3 concentration of sulfur dioxide (SO2) gas to ppm at 100C and 770 mmHg. Styrene is a volatile organic compound than can exist in air as a gaseous pollutant. Convert a 20 ppm volume ratio of styrene gas in air to mg/m3 at 50C and 750 mmHg. The molecular weight of styrene is 104.15 g/mol. Assume that at this concentration level, the FE handbook interconversion formula is applicable for this substance. (answer: 77.52 mg/m3)