Apr 1, 1980 - Pressure measuring devices and pressure calculations. Charles W. Schultz. J. Chem. Educ. , 1980, 57 (4), p 285. DOI: 10.1021/ed057p285.1...
be able to distinguish two kinds of pressure: Boyle's Law pressure of a gas (which depends on volume) from the equi- librium vapor pressure above a liquid ...
55-gal. organic solvent drum on a day when the temperature was 25'C and atmospheric pressure was 740 mm, and found that 25 gal. of liquid remained. After the drum was tightly resealed, a fork lift operator dented the drum reducing the interior volume
After the drum was tightly resealed, a fork lift operator dented the drum reducing the interior volume to 45 gal. If the vapor pressure of the organic solvent at 25°C ...
oberated under extreme conditions are largely a matter of experience. But here are workable ... ment long before such conditions reach the plant. Specific cases.
This question requires students to be able to distinguish two kinds of pressure: Boyles law pressure of gas (that depends on volume) from the equilibrium vapor ...
JACK H. THELIN1, Rutgers University, New Brunswick, N. J. THE regulators described in this article resulted from a need for a sensitive and positive vacuum.
Graphene-Based Device Enables Active Thermal Camouflage. Researchers have made a thermal camouflage device from graphene that can adjust how much .
This membrane permitted the passage of molecules of solvent and held back those of the solute. The difficulties in obtaining a satisfactory mem- brane are ...
method of measuring osmotic pressure, applicable in many instances in which the previous methods could not be applied, and which greatly extends the ...
UNUSUAL PRESSURE RELIEF DEVICES. R. L. Porter. Ind. Eng. Chem. , 1962, 54 (1), pp 24â27. DOI: 10.1021/ie50625a004. Publication Date: January 1962.
E=
6.62
X
lo-"
J sec X 2.998 X m 2.000 X
lo8 m sec-' = 9.92 X 10-I9 3 molecule-'
9.92 x 10-'9 X 6.023 X Hence 0~and
loz3= 598 kJ mole-'
Hz can be phornrh~mi~~lly disso~.iatedi n the upper
atmusphere; mdted O7 is prncr~cnllyall diisociarcd in this regmn. 6.67 X lo-'' X 6.5 X (2) Escape velocity of Mars = 3.5 X 106
(3
8.314 X 1500)lm 28 X = 1.16 X 103 m sec-I (3 X 8.314 X 1500)lm Velocity of dioxygen molecules = 32 X = 1.08 X lo3 m seer1
Velocity of dinitrogen molecules =
X
From the above table we get for ratios of (?)"%. molecule
(3"*lvs
predicted time of half-life
N2
0.33 0.31
1010 years 10'O years
02
This clearly indicates that slower moving diaxygen molecules should have a comparable half-lifeto dinitrogen. However, this does not seem to he the case empirically. An explanation comes forward if Oz is considered to be dissociated in the Martian exosphere-as on Earth. X 8.314 X 1500)'/1 velocity of oxygen atoms = 16 X
(3
The ratio ( ~ ) ' " l u . here = 0.44 which indicates a half-life for oxygen of -10" "ears..much smaller than the Universal ace. Hence the Martian ntmmphcre isdepleted in O1hy this t w - d a y ? mechanism. CH4 rmdnrmns~16 X 10- kg)nnd I\'HI
