Tricarbonyl(methylcyclopentadienyl)manganese

Vapour pressure

Link to relevant study record(s)

Reference

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Not mentioned

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Qualifier:

no guideline followed

Principles of method if other than guideline:

Methodology used is decribed below.

GLP compliance:

no

Remarks:

Study conducted prior to introduction of GLP

Type of method:

dynamic method

Key result

Temp.:

ca. 26.1 °C

Vapour pressure:

ca. 0.073 mm Hg

Remarks on result:

other: Average of Run 1 and Run 2

Temp.:

ca. 26.1 °C

Vapour pressure:

ca. 0.069 mm Hg

Remarks on result:

other: Run 1

Temp.:

ca. 26.1 °C

Vapour pressure:

0.077 mm Hg

Remarks on result:

other: Run 2

Temp.:

ca. 27.2 °C

Vapour pressure:

ca. 0.082 mm Hg

Remarks on result:

other: Run 3

Table 1 - Vapor pressure of mmt

Temperature of the wet test meter, ºC	Run
	1	2	3
	26.1	26.1	26.7
Temperature of the six mmt Scrubbers, ºC	26.1	26.1	27.2
Temperature of the Chromosorb, ºC	26.1	26.1	27.2
Barometer, mm Hg	742.2	741.5	738.0
Manometer (pressure drop in Chromosorb), mm Hg	22	22	22
Air volume (wet test meter), liters	5.64	11.27	15.78
Air flow rate, ml/min	50	50	50
Manganese on Chromosorb, mg	1.12	2.50	3.685

Using the data above the vapour pressure of mmt was calculated using the following equations:

 

The weight of Mn in a molar volume = (weight of Mn on Chromosorb x 22.4) / volume of air

 

Vapour pressure = (wt of Mn / molar vol x 760) / atomic wt. of Mn

 

Combining these equations and applying corrections for temperature and barometric pressure we obtain:

 

Vapour pressure mmt = (Gm of Mn on Chromosorb) x 22.4 x 7.60 x (273 + ºC) x 760) / ((volume of air) x 54.94 x 273 x Barometer)

 

This equation was used to calculate the data in Table 2. Table 2 – Vapour pressure of MMT mm Hg

	Vapour pressure of mmt mm Hg
Run 1 at 26.1 ºC (79 ºF)	0.069
Run 2 at 26.1 ºC (79 ºF)	0.077
Run 3 at 27.2 ºC (81 ºF)	0.082

Conclusions:

The vapour pressure of mmt at 26.1 ºC is 0.073 mmHg.

Description of key information

The key study defines the average vapour pressure of mmt at 26.1°C as 0.073 mmHg. Using the conversion factor from mmHg to Pa of 133.3 the vapour pressure of mmt is 9.73 Pa.

Key value for chemical safety assessment

Vapour pressure:

9.73 Pa

at the temperature of:

26.1 °C

Additional information

Three studies are available that define the vapour pressure of mmt. Supporting study results are consistent with key study data.