Question

A student breaks a thermometer and spills most of the mercury (Hg) onto the floor of a laboratory that measures 15.2 m long, 6.6 m wide, and 2.4 m high.
(a) Calculate the mass of mercury vapor (in grams) in the room at 20°C. The vapor pressure of mercury at 20°C is 1.7 × 106 atm.
(b) Does the concentration of mercury vapor exceed the air quality regulation of 0.050 mg Hg/m3 of air?
(c) One way to treat small quantities of spilled mercury is to spray sulfur powder over the metal. Suggest a physical reason for this action.

Answer 1

Convert the measurements to volume; i.e., v = length x width x height. You will have volume in cubic meters.
Use PV = nRT and solve for n = mol Hg.
Convert mols to grams. g = mols x atomic mass.
That gets a. You can do the comparison for b.
c. Chemical reason might be formation of HgS. Physical might be to serve as a cap or cover for the spill. Over time I don't think that will be effective as the vapor pressure, at equilibrium, will be the same whether covered or uncovered; however, it will take longer to reach equilibrium.

Answer 2

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