Dichlorodifluoromethane

Vapour pressure

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Remarks:

Taken from publicly available data, and is considered accurate based on the registrants experience of the substance.

Qualifier:

no guideline available

Principles of method if other than guideline:

Not specified

GLP compliance:

not specified

Type of method:

other: Not specified

Temp.:

20 °C

Vapour pressure:

4 306 Torr

Remarks on result:

other: Equates to 574.086 kPa

Conclusions:

Vapor pressure at 20°C: 4306 torr = 574.086 kPa (Pearson and McConnell, 1975). These references value closely match the registrants experience of the substance and is considered suitable for use, on the basis of a weight of evidence approach.

Executive summary:

Vapor pressure at 20°C: 4306 torr = 574.086 kPa (Pearson and McConnell, 1975). These references value closely match the registrants experience of the substance and is considered suitable for use, on the basis of a weight of evidence approach.

Reference 2

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

Not specified.

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Principles of method if other than guideline:

No details provided on the method used.

GLP compliance:

not specified

Type of method:

other: Not specified.

Key result

Temp.:

70 °F

Vapour pressure:

84.8 PSI

Remarks on result:

other: equates to 584.68 kPa at 21.11°C

Conclusions:

Vapor pressure at 70°F: 84.8 psia. This equates to 584.68 kPa at 21.11°C. These references value closely match the registrants experience of the substance and is considered suitable for use, on the basis of a weight of evidence approach.

Executive summary:

Vapor pressure at 70°F: 84.8 psia. This equates to 584.68 kPa at 21.11°C. These references value closely match the registrants experience of the substance and is considered suitable for use, on the basis of a weight of evidence approach.

Reference 3

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Principles of method if other than guideline:

The measurements were performed with an apparatus which was specially developed for accurate measurements of the saturated-liquid and saturated-vapour densities of pure substances together with the vapour pressure along the whole coexistence curve. Moreover, the apparatus is also suitable for density measurements of the homogeneous gas or liquid phase including the largest part of the critical region. The principle of density measurement is based on a new compensation buoyancy-method using two sinkers instead of the usual single sinker ("Two-Sinker Method"). The essential details of the apparatus were given in a previous paper (Kleinrahm and Wagner, J.Chem. Thermodynamics 1986, 18, 739). Up to now this apparatus has been used for comprehensive measurements of methane and of carbon dioxide.

GLP compliance:

not specified

Type of method:

other: saturated-liquid and saturated-vapour densities

Key result

Temp.:

300 K

Vapour pressure:

683.8 kPa

Remarks on result:

other: The value quoted is an average value of the two pressures presented at 300 K (eq to 26.85°C) of 0.683773 and 0.683824 MPa respectively.

(p,p,T) measurements of dichlorodifluoromethane (R12) in the homogeneous gas and liquid regions, where T is the temperature (IPTS-68), p the pressure, and p the density.

p	p	p	p	p	p	p	p
MPa	Kg m^-3	MPa	kg m^-3	MPa	kg m^-3	MPa	kg m^-3
T= 150.000 K
0.521070	1740.14	2.01836	1741.95	4.9402	1745.37	7.93132	1748.84
0.706551	1740.41	2.09491	1742.01	5.38984	1745.91
1.46669	1741.30	4.89954	1745.31	7.85308	1748.71
T= 200.000 K
0.105606	1608.12	1.35691	1610.43	5.01437	1617.05
0.683103	1609.19	2.00173	1611.64	7.61158	1621.62
0.691904	1609.21	4.02274	1615.28	7.82172	1621.93
T= 250.000 K
0.1968867	1467.69	0.623629	1469.07	2.00453	1473.34	5.98339	1485.05
0.214425	1467.7	1.20441	1470.88	5.03220	1482.32	7.95081	1490.57
0.568089	1468.87	1.54731	1471.92	5.06294	1482.41	8.00105	1490.69
0.627396	1469.05	1.99882	1473.33	5.11701	1482.58
T= 260.000 K
0.088605	5.0877	0.188940	11.2128	0.193126	11.4777
0.088914	5.1057	0.190701	11.3243	0.193679	11.5129
0.171486	10.1157	0.191630	11.3830	0.194166	11.5436
T= 300.000 K
0.196023	9.8656	0.625871	34.8378	0.882549	1305.66	2.02310	1312.74
0.196579	9.8955	0.653242	36.6409	0.989723	1306.27	2.07618	1313.05
0.197690	9.9534	0.660564	37.1292	1.28087	1308.08	3.53347	1321.65
0.378700	19.8197	0.669299	37.7131	1.28596	1308.14	4.85560	1329.00
0.386229	20.2483	0.670567	37.7989	1.28943	1308.16	5.01835	1329.86
0.486436	26.1127	0.678337	38.3227	1.46784	1309.31	6.53294	1337.77
0.545300	29.7091	0.709733	1304.46	1.50036	1309.49	7.92885	1344.66
0.589405	32.4849	0.882592	1305.56	1.53267	1309.70	8.03605	1345.17
T= 330.000 K
0.203561	9.2284	0.933834	47.9897	1.36495	77.9373	1.39835	80.6397
0.440353	20.6947	1.18146	64.2157	1.38693	79.7066	1.40849	81.4790
0.616964	29.8591	1.33082	75.2468	1.39194	80.1143

 

Experimental results for the vapour pressurep_ō, the saturated-liquid density p’, and the saturated-vapour density p”,of dichlorodifluoromethane (R12), whereTis the temperature (IPTS-68)

T	p”	pō	p’	pō	T	p”	pō	p’	pō
K	kg m^-3	MPa	kg m^-3	MPa	K	kg m^-3	MPa	kg m^-3	MPa
120.000			1818.42		260.000			1437.30	0.195368
120.000			1818.45		260.000				0.195369
130.000			1791.93		270.000		0.277449
140.000			1765.68		270.000			1406.09	0.277562
150.000			1739.56		270.000				0.277658
160.000			1713.47		280.000		0.383596
160.000			1713.52		280.000		0.383626
170.000			1687.35		280.000			1373.68	0.383694
180.000		0.002248	1661.07		280.000				0.383845
180.000				0.002218	290.000		0.517561
190.000			1634.64	0.004922	290.000		0.517628
200.000			1607.96	0.010008	290.000				0.517586
210.000			1580.89	0.018854	290.000				0.517647
220.000			1553.43	0.033180	290.000				0.517653
220.000			1553.44		290.000			1339.84	0.517786
220.000			1553.46		290.000				0.517925
230.000			1525.45	0.055227	300.000	38.6912	0.683773
240.000			1496.84	0.087569	300.000		0.683824
240.000				0.087583	300.000			1304.29	0.683880
245.000				0.108536	300.000				0.684095
245.000				0.108546	300.000			1304.29
250.000			1467.54		310.000			1266.64	0.886405
250.000			1467.55		310.000		0.886481
255.000				0.161984	320.000			1226.38	1.12996
255.000				0.161993	320.000		1.13019
255.000				0.161993	320.000			1226.33
260.000		0.195187			320.000			1226.36	1.13070
260.000		0.195221			330.000			1182.77	1.41971
260.000	11.6130	0.195259			330.000	82.4281	1.41994
260.000			1437.34	0.194168	340.000			1134.75
260.000				0.195353

 

Conclusions:

The study focuses on the pressure, density, temperature) relations of dichlorodifluoromethane (R12) and of chlorodifluoromethane (R22) in parts of the homogeneous gas and liquid regions and on the coexistence curve of the substance.

The study details vapour pressures over a wide range of temperatures for the substance. The value quoted in this summary is an average value of the two pressures presented at 300 K of 0.683773 and 0.683824 MPa respectively. These values match with other data available and is considered appropriate for use on the basis of a weight of evidence approach.

Executive summary:

The study focuses on the pressure, density, temperature) relations of dichlorodifluoromethane (R12) and of chlorodifluoromethane (R22) in parts of the homogeneous gas and liquid regions and on the coexistence curve of the substance.

The study details vapour pressures over a wide range of temperatures for the substance. The value quoted in this summary is an average value of the two pressures presented at 300 K (i.e., 26.85°C) of 0.683773 and 0.683824 MPa respectively. These values match with other data available and is considered appropriate for use on the basis of a weight of evidence approach.

Reference 4

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

Not applicable

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Principles of method if other than guideline:

The static equilibrium apparatus and the procedures used for this work are described by Kang and Lee (1996). The equilibrium temperature was measured with a T-type thermocouple converter (Yokogawa Elec. Corp., model STED-210-TT*B) having an accuracy of +/- 0.1 °C. The equilibrium pressure was determined by a gauge pressure transmitter (Yokogawa Elec. Corp., model UNE43-SAS3*B) and a barometer having accuracies of +/- 0.5 kPa and +/- 0.05 kPa, respectively.
The mass of each component introduced into the cell was determined with a digital balance having an accuracy of +/-0.01 g. The compositions of the vapor phase were not measured. The compositions of the liquid phase were calculated from the total composition by correction for the mass of each component existing in the vapor phase. The densities of the both phases were estimated by using the Peng-Robinson equation of state (1976) with the binary interaction parameters obtained by data reduction of the experimental data. Factors affecting the accuracy of the liquid-phase mole fractions would be the accuracy of the masses of each component introduced into the cell and the estimated densities of both phases. The effect of 10% errors in the estimated densities for the liquid and the vapor phase gives an error of approximately 0.0001 and 0.0005 in the respective mole fraction. The estimated accuracy of the liquid-phase composition was +/- 0.001.

GLP compliance:

not specified

Type of method:

other: Isothermal vapor-liquid equilibria

Temp.:

-30 °C

Vapour pressure:

4 129 kPa

Vapour-Liquid Equilibria for CFC-12 (1) + Chlorine (2) at 10.0°C

P/kPa	x1	y1(calcd)	P/kPa	x1	y1(calcd)
502.1	0.0000	0.0000	518.3	0.4495	0.4072
511.2	0.0484	0.0630	513.4	0.5004	0.4486
517.9	0.1000	0.1190	508.0	0.5487	0.4894
521.9	0.1520	0.1683	501.7	0.5988	0.5335
524.4	0.1995	0.2094	494.7	0.6487	0.5795
523.3	0.2503	0.2509	485.9	0.6995	0.6290
525.0	0.3013	0.2911	477.1	0.7517	0.6831
523.8	0.3497	0.3287	467.9	0.7995	0.7357
521.6	0.3997	0.3677	457.0	0.8504	0.7956
518.3	0.4502	0.4078	447.0	0.8952	0.8521
514.0	0.4993	0.4477	435.3	0.9501	0.9265
			422.6	1.0000	1.0000

Binary Parameters of the Peng-Robinson Equation of State and Standard Deviations of the Measured Variables for the Binary Systems

System	t/°C	012	Standard deviations
			P/kPa	t/°C	100x1
CFC-12 (1) + Chlorine (2)	10.0	0.0075	0.2	0.02	0.00

Conclusions:

The study focuses on the Isothermal Vapor-Liquid Equilibria of the substance. However, the vapour pressure is reported for the pure substance at -30 deg C as 4129 kPa. This is the approximate boiling point of the substance and is considered to be just above the saturation temperature.

Executive summary:

The study focuses on the Isothermal Vapor-Liquid Equilibria of the substance. However, the vapour pressure is reported for the pure substance at -30 deg C as 4129 kPa. This is the approximate boiling point of the substance and is considered to be just above the saturation temperature.

Reference 5

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

Not specified

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Principles of method if other than guideline:

No method specified.

GLP compliance:

not specified

Type of method:

other: No method specified.

Key result

Temp.:

30 °C

Vapour pressure:

7.6 atm

Remarks on result:

other: Equates to 770.1 kPa.

Key result

Temp.:

20 °C

Vapour pressure:

4 250 mm Hg

Remarks on result:

other: Equates to 566.6 kPa.

Conclusions:

Two values are presented, as follows:

Equates to 770.1 kPa. 30°C
Equates to 566.6 kPa. 20°C

These references value closely match the registrants experience of the substance and is considered suitable for use, on the basis of a weight of evidence approach.

Executive summary:

Two values are presented, as follows:

Equates to 770.1 kPa. 30°C

Equates to 566.6 kPa. 20°C

These references value closely match the registrants experience of the substance and is considered suitable for use, on the basis of a weight of evidence approach.

Description of key information

Vapour pressure: 566.6 kPa at 20°C

Key value for chemical safety assessment

Vapour pressure:

566.6 kPa

at the temperature of:

20 °C

Additional information

Five references are available for review. The reference values closely matches the registrants experience of the substance and is considered suitable for use, on the basis of a weight of evidence approach. The value at 20 deg C is chosen as the most appropriate one for use in the assessment process, as this closely matches values obtained from the other studies.