Calculations are not required for this question beyond very basic unit conversio

Question

Calculations are not required for this question beyond very basic unit conversion. Dr. Beal, new Catering Director for SkyChef, thinks that it would be a fine idea to go intothe cargo compartment of a jetliner flying at 11000 m (36000 ft) and boil some chicken legs for dinner. He found that it was impossible to properly cook the meat to 74°C(165°F), the safe minimum cooking temperature. Given the two pieces of data below and your knowledge of physical chemistry, explain to him why this was not such a good idea.

Atmospheric pressure as a function of altitude (from Ahrens, Meterology Today)

Vapor pressures of water at selected temperatures (from Tro, Chemistry: Structure andProperties)

Explanation / Answer

From the first graph: the atmospheric pressure at 11 000 m altitude is

300 mbar = 0.3 bar = 0.3 bar x 760 torr/bar = 228 torr.

From the Table: At about 69ºC, the vapour pressure of water is also 228 torr.

It means that in the cargo compartment water boils at about 69ºC, so SkyChef can’t cook the meat at 74 ºC.

Note: a liquid boils at the temperature at which its vapour pressure becomes equal to the atmospheric pressure.

Related Questions

Navigate

• Browse (All)
• Browse C
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.