Question

What is the parts per million (ppm) of styrene in this enclosure?

The enclosure is 8 x 3 x 3 ft large. Liquid styrene accounts for 4 percent of the size of a tank within the enclosure which is 20 x 20 x 8 inches. What is the ppm of the air?

Styrene has a chemical formula of C6H5CH=CH2. The density of styrene is 0.906 g/cm^3.

Also, according to the cdc, for styrene, 1 ppm = 4.26 mg/m^3

Answer 1

Given data:

The volume of an enclosure = 8 x 3 x 3 ft³, i.e. 2.04 m³.

The volume of a tank within the enclosure = 20 x 20 x 8 in³, i.e. 0.05 m³.

The volume of styrene = 4% of the volume of a tank, i.e. 0.002 m³.

The density of styrene = 0.906 g/cm^3 = 906 Kg/m³.

Mass of styrene = 906*0.002, i.e. 1.812 Kg

Volume of air = (Enclosure's volume - 96% of Tank's volume), i.e. 1.992 m³.

The density of air = 1.22 Kg/m³.

Mass of air = 1.22*1.992, i.e. 2.43 Kg.

Mass fraction for styrene = 1.812/(1.812 + 2.43), i.e. 0.43

Therefore, Concentration of styrene in the given enclosure = 0.43*906*10⁶/4.26 ppm, i.e. 9.1*10⁵ ppm

Mass fraction for air = 1 - 0.43 = 0.57

Therefore, Concentration of air in the given enclosure = 0.57*1.22*10⁶/4.26 ppm, i.e. 1.6*10⁷ ppm