Pentan-2-one

Boiling point

Link to relevant study record(s)

Reference

Endpoint:

boiling point

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2013

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

EU Method A.2 (Boiling Temperature)

Deviations:

no

GLP compliance:

no

Type of method:

photocell detection

Boiling pt.:

102.7 °C

Atm. press.:

101 325 Pa

*INFORMATION REQUIREMENTS- Study does not need to be conducted for gases, or for solids which either melt above 300C or decompose before boiling, or substances which decompose before boiling.

 

METHOD

 

The boiling point measurement was conducted using a photocell detection method which employs a Mettler FP90 temperature control module and a Mettler FP81HT measurement cell. The tests were conducted according to Method A2 of Commission Directive 92/69/EEC (which constitutes Annex V of Council Directive 67/548/EEC). 

 

PROCEDURE

 

 A reference material, m-xylene, was first run to confirm the accuracy of the method. The boiling point of m-xylene corrected to 760 Torr was determined to be 139.4 ⁰C, compared to the reference value of 139.1 ⁰C from reference V-1.

 

The sample was placed in a glass boiling point tube to height of 15 mm. A boiling point capillary was inserted into the sample to act as a boiling chip. The boiling point tube was then inserted into the instrument and the sample temperature was increased to approximately 30 °C below the expected boiling point. The sample temperature was controlled by the FP90/FP81HT system as was the detection of the boiling point of the sample. The temperature of the sample was increased at a rate of 1 ⁰C/minute until the instrument detected boiling of the sample. Boiling is optically detected by a photocell in the FP81HT. The boiling point is defined as the point when the bubble rate in the sample tube reaches 0.6 Hz. The boiling point at barometric pressure is then corrected by the instrument to 760 Torr using the Clausius-Clapeyron equation.

CALCULATIONS

A boiling point not measured at 760 Torr (sea level) must be corrected in order to be reported as standard or normal boiling point. The following correction is based on the Clausius-Clapeyron equation assuming an entropy of vaporization of 94 J/mol-K. This correction is performed automatically by the Mettler FP90 temperature control module:

 

T_std= T_p+ (T_p[K]*ln (p_std/p))/11.3

 

where

 

T_std        = boiling point corrected to 101325 Pa, expressed in ⁰C

T_p         = boiling point measured at barometric pressure p, expressed in ⁰C

T_p[K]     = boiling point measured at barometric pressure p, expressed in Kelvin

p_std        = 101325 Pa

p            = barometric pressure during boiling point determination, expressed in Pa

 

For this measurement, T_p= 101.4 ⁰C, T_p[K] = 375.6 K, p = 97400 Pa.

 

RESULTS/CONCLUSION

 

The boiling point corrected to 101325 Pa was determined to be 102.7 +/- 1 °C.

 

REFERENCES

 

V-1. R. Chirico, S. Knipmeyer, A. Nguyen, J. Reynolds, W. Steele, "Thermodynamic Equilibria in Xylene Isomerization. 2. The Thermodynamic Properties of m-Xylene", J. Chem. Eng. Data, Vol. 42, p. 475, (1997).

Conclusions:

The boiling point corrected to 101325 Pa was determined to be 102.7 +/- 1 °C.

Executive summary:

The boiling point corrected to 101325 Pa was determined to be 102.7 +/- 1 °C.

Description of key information

The boiling point corrected to 101325 Pa was determined to be 102.7 +/- 1 °C.

Key value for chemical safety assessment

Boiling point at 101 325 Pa:

102.7 °C