# Problem: Mercury (Hg) vapor is toxic and readily absorbed from the lungs. At 20.°C, mercury (ΔHvap = 59.1 kJ/mol) has a vapor pressure of 1.20 x 10−3 torr, which is high enough to be hazardous. To reduce the danger to workers in processing plants, Hg is cooled to lower its vapor pressure. At what temperature would the vapor pressure of Hg be at the safer level of 5.0 x 10−5 torr?

###### FREE Expert Solution

For this problem, we can use the Clausius-Clapeyron Equation:

where:

P1 = vapor pressure at T1

P2 = vapor pressure at T2

ΔHvap = heat of vaporization (in J/mol)

R = gas constant (8.314 J/mol•K)

T1 and T2 = temperature (in K).

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###### Problem Details

Mercury (Hg) vapor is toxic and readily absorbed from the lungs. At 20.°C, mercury (ΔHvap = 59.1 kJ/mol) has a vapor pressure of 1.20 x 10−3 torr, which is high enough to be hazardous. To reduce the danger to workers in processing plants, Hg is cooled to lower its vapor pressure. At what temperature would the vapor pressure of Hg be at the safer level of 5.0 x 10−5 torr?