formaldehyde - Sciencemadness Dot Org

.32 FORMALDEHYDE
Partial Pressure, The partial pressure of formaldehyde over its pure
-„.; :•>• .-> *:.->.::ior_* wa* studied by Auerbaeh and Barschall 4 - \ Ledbury and
H'.air :: . ui;i Iv rzhev &ud Rossinskaya 16 . As previously pointed out
:-:.:«.- 33-34 . deviations ui formaldehyde partial pressures from those
v.-i.i:'":. -.v> -:;M :.-t- rxpeeted from Raoult's and Henry's laws maj- be explained
" y -ira; Lvdratiuii o: dissolved formaldehyde and the increasing proportion
*-: noIvir.erL:- hydrates at low temperatures and high concentrations.
X::b> V. Par:Iil Pressure asd Air Saturation Data for Aqueous Formaldehyde.*
Partial Pressure of Mg Formaldehyde
rimii'.iehyde C.:^:e"::^::or. Formaldehyde per Liter
^ TH:C !:•: ^. ^-CH.O 1. c- mm) Saturated Air
» .i> t
15. u
7 9 4
^S.6
£.25
IS.6
27.2
2S.S
36.2
1.0S
5.10
11,4
1S.3
19.7
2S.6
35,9
10.5
19.4
27.1
35.5
- . ' j ^ -
15.6S
20.63
31.25
9.-52
19.7
29.5
31.1
40,2
1.09
5.15
11.6
IS.6
20.S
31.0
39.5
10.S
20.4
2S.75
39.2
* Data of Ledbury and Blair.
Te; mperature i = 0 C C
0.056
0.102
0.I1S
0.157
Ten vperature
Temperature
Temperature
= 20°C
0.340
0.575
0.7S0
0.795
1.025
- 8$*C
0.166
0.695
1.29
1.S0
1.94
2.4S
2.SI
= 4S°C
2.30
3.79
4,72
5.60
0.095
0.166
0.201
2.265
0.59
1.01
1.39
1,40
1.75
0-27
1.13
2.06
2,87
3.17
4.27
4.r
3.77
6.17
7.70
9.12
The partial-pressure data of Ledbury and Blair 13 cover solutions containing
up to 37 per cent formaldehyde at temperatures of 0 to 45°C.
They were determined by measuring the formaldehyde content of air
which had Iseen passed though scrubbers containing solutions of definite
temperature and concentration at equilibrium conditions. Formaldehyde
concentrations were reported by these investigators in volume per cent.
To conform with present American practice, we have converted their
figures to the weight per cent basis in Table 9. The formaldehyde content
of air in equilibrium with solution is given in the same table Ln terms of mg
of formaldehyde per liter. The relation of these partial pressure values
to concentration is shown graphically in Figure 10.