Question

If a 0.5 L bottle (under

50 bar pressure) of boron trifluoride (BF3) leaks into a 1000m^2

cleanroom, will it be immediately dangerous to health? and why?

Answer 1

Volume of BF3 = 0.5 L

Pressure P = 50 bar

Room temperature T = 27 + 273 = 300 K

From the ideal gas equation

Moles of BF3 = PV/RT

= ( 50 bar x 0.987atm/bar x 0.5 L) / (0.0821 L-atm/mol-K x 300K)

= 1.01 moles

At STP, Volume of BF3 in cleanroom = 1.01 mol x 22.4L/mol

= 22.624 L

Volume of room = height x area

= 3 m x 1000 m2 = 3000 m3 x 1000L/m3

= 3 x 10^6 L

Concentration of BF3 in ppm = 22.624*10^6/(3*10^6)

= 7.5 ppm

Yes it is immediately dangerous to health because it is higher than the threshold limit of 0.05 ppm and 4 times higher the threshold value (2 ppm) is life threatening.