Registration Dossier

Diss Factsheets

Physical & Chemical properties

Melting point / freezing point

Currently viewing:

Administrative data

Endpoint:
melting point/freezing point
Type of information:
experimental study
Adequacy of study:
key study
Study period:
03.08.2021
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2021
Report date:
2021

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
EU Method A.1 (Melting / Freezing Temperature)
Deviations:
not specified
Qualifier:
according to guideline
Guideline:
OECD Guideline 102 (Melting point / Melting Range)
Version / remarks:
1995
Deviations:
not specified
GLP compliance:
no
Type of method:
differential scanning calorimetry

Test material

Constituent 1
Chemical structure
Reference substance name:
4-chlorobenzoic acid
EC Number:
200-805-9
EC Name:
4-chlorobenzoic acid
Cas Number:
74-11-3
Molecular formula:
C7H5ClO2
IUPAC Name:
4-chlorobenzoic acid
Test material form:
solid: particulate/powder
Details on test material:
white to yellowish crytalline powder

Results and discussion

Melting / freezing point
Key result
Melting / freezing pt.:
239.2 °C
Atm. press.:
1 012 hPa
Decomposition:
no

Any other information on results incl. tables

In the temperature range of 230 – 260 °C, an endothermic effect was observed. Between 260 – 300 °C a second endothermic effect could be detected. No further thermal effects were observed up to the test end temperature of 500 °C.

Table 1:    Results of the DSC-measurements

Measurement No.

Sample weight /
mg

Onset of Effect /
°C

Range of effect /
°C

Weight loss /
mg

Atmospheric pressure /
hPa

Remark

PN20973

11.07

239.12
277.83

230 – 260 (endo)
260 – 300 (endo)

11.07

1012.2

Figure 1

PN20974

11.17

239.36
277.69

230 – 260 (endo)
260 – 300 (endo)

11.17

1012.1

Figure 2

During the heating phase a distinct endothermic effect was observed in the temperature range of 230 – 260 °C, which can be assigned to the melting of the test item.

As the onset temperatures in both tests do not deviate by more than 0.5 K from their mean value of 239.24 °C, this temperature can be used as melting point. The test item has a melting point of 239.2 °C.

The test item showed a second endothermic signal in the temperature range of 260 – 300 °C, which could be assigned to the boiling of the test item.

For the correction of the boiling temperature to standard pressure the test item was assigned to chemical group 5 (e.g. Benzoic acid). According to appendix 8.2a correction value φ = 5.85 was used for the temperature range from 270 °C to 280 °C.

The lowest measured onset temperature is corrected to the standard pressure to be 277.73 °C and the highest onset temperature to be 277.87 °C. As the corrected onset temperatures in both tests do not deviate by more than 0.5 K from their mean value of 277.80 °C, this temperature can be used as boiling point. The test item has a boiling point of 277.8 °C.

Applicant's summary and conclusion

Conclusions:
4-Chlorobenzoic acid has a melting point of 239,2 °C at atmospheric pressure (1012 hPa).
Executive summary:

The test item p-Chlorobenzoic acid has a melting point of 239,2 °C at atmospheric pressure (1012 hPa) as determined by Differential Scanning Calorimetry according to Regulation (EC) No 440/2008 Method A.1. and OECD Test Guideline 102 (1995).