A Sherpa on lop of Mt. Everest (altitude = 29,000 ft above sea level) decides th
ID: 1007404 • Letter: A
Question
A Sherpa on lop of Mt. Everest (altitude = 29,000 ft above sea level) decides that he wants to boil some water so that he can cook noodles for his fellow mountaineers. At that altitude, the air pressure is only 242 mm Hg which is about a third of the air pressure at sea level. At what temperature (in degree C) will the water boil on the top of Mt. Everest? b) The element, gallium (Ga), is a liquid metal at room temperature. Gallium has a density of 6.1 g/mL, a boiling point of 2200 degree C and a heat of vaporization of 254 kJ/mol. At its normal boiling point, what will be the vapor pressure (in mm Hg) of 50 g of gallium?Explanation / Answer
From Classius- Clayperon equation
Ln(P2/P1)= (deltaH/R)*(1/T1-1/T2)
Where P2= 760mm Hg and P1= 242 mm Hg
T2= 100 deg.c= 100+273.15= 373.15
T1= ?
deltaH= 40.5*1000 j/mol
R= 8.314 J/mol.K
Ln(760/242)= (40.5*1000/8.314)*(1/T1-1/373.15)
0.000235= 1/T1-0.00268
1/T1= 0.002915, T1= 343K= 343-273.15=69.85 deg.c
2. Normal boiling point refer to 760 mm Hg. so the vapor pressure of Gallium at normal boiling point is 760 mm Hg