Vapor Pressure of White Phosphorus From 44° to 150°.

Abstract

mechanical strength must be attributed to solution forces, the system being physically homogeneous down to molecular and submolecular dimensions.-4 more complete survey of the elastic constants, particularly of the time of relaxation, in relation to composition and treatment, is now in progress, both mechanical and optical methods being used. It is believed that the comparison of mechanical and optical methods will permit a inore definite allocation of the respective types of structure. Summary. 1. ,S?Ieasurements of the rigidity of gelatin jellies are given, shun big that the jellies follow Hooke's lair nearly up to the breaking point. 2. The relation of the modulus of clasticity to the concentration uf gelatin is discussed; it is found that a function of the type E = kcn is ralid for a certain range, but the constants k and 71 may vary from one grade of gelatin to another. 3. The influence of acidity and alkalinity on the elasticity has been followed quantitatively. PH measurements show that the observed variations of elasticity are not a simple function of the actual hydrogen-ion concentration. 4. The influence of alcohol and glycerin in different concentrations on the coefficient of rigidity has been measured. ROCABSTTR, hT. Y. [CONTRIBUTION FROM RESEARCH LABORATORY OF \vESTINLHOUSE L.4MP COMPAhY 1 VAPOR PRESSURE OF WHITE PHOSPHORUS FROM 44" TO 150".

Enthalpy of formation of phosphorus pentachloride; derivation of the enthalpy of formation of aqueous orthophosphoric acid

“…Andrews [26] reacted in a closed glass vessel at about atmospheric pressure a known volume of chlorine, measured dry at 11.4 °c and 29.85 in Hg, with an excess of phosphorus. In two runs he obtained 1924.6 and 1926.1 g-ca1/(1000 cm 3 Clz at 0 °c, 1 atm). Average calorimeter temperature during the runs was 11.6 0c.…”

“…This quantity, denoted h, is calculated by the formula: [(37,943.11 + aEs) I1R c+ 12.38 v -0.479(1.594 wI! +O.lOO) 3 . p3 + /P in table 2 is the mol ratio of trivalent phosphorus to total phosphorus in the products, equal to 0.00225 v/w).…”

“…The apparatus was then sealed at S2 and pumped down to 10-3 mm Hg to remove the water. After the solidified phosphorus was dry and had begun to sublime over at 25°C (equilibrium vapor pressure = 0.04 mmHg [3]), an ice bath was placed around the condenser (C). During the next twenty hours , while the pumping continued at mmHg, about ninety percent was trapped in the condenser (C) at 0 °C (equilibrium vapor pressure = 0.005 mmHg [3]) as colorless well-formed crystals , while some phosphorus vapor with impurities was continuously carried on to the liquid-nitrogen trap (E).…”

“…After the solidified phosphorus was dry and had begun to sublime over at 25°C (equilibrium vapor pressure = 0.04 mmHg [3]), an ice bath was placed around the condenser (C). During the next twenty hours , while the pumping continued at mmHg, about ninety percent was trapped in the condenser (C) at 0 °C (equilibrium vapor pressure = 0.005 mmHg [3]) as colorless well-formed crystals , while some phosphorus vapor with impurities was continuously carried on to the liquid-nitrogen trap (E). The pressure was then reduced to less than mmHg by a mercury-diffusion pump, all parts containing phosphorus were cooled by liquid nitrogen, and the yellow-phosphorus chamber (B) was sealed at S3.…”

“…The disengaged ampoul e containing the reaction produ cts was brok en ope n at th e neck , jus t above the reaction cha mber , and the sm all amount of P Ch in the tubular portion was washed with water into approximately 200 cm 3 of wate r co ntainin g 100 mg of hydrazin e dihydroc hloride in a 500-cm 3 Erle nmeyer flas k with fluoro carbon-gask e ted glass -stoppered closure. The reaction cha mber , co ntainin g nearly all the products of reaction , was the n placed in th e Erle nm e yer flask whi c h was ti ghtly closed a nd s ha ken.…”