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EC number: 200-848-3 | CAS number: 75-20-7
Henry's Law constant
Administrative data
Link to relevant study record(s)
- Endpoint:
- Henry's law constant
- Type of information:
- read-across from supporting substance (structural analogue or surrogate)
- Adequacy of study:
- supporting study
- Study period:
- 2014
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- other: Read across from calculation of a surrogate substance
- Justification for type of information:
- As calcium carbide instantly hydrolyses to Ca(OH)2 and C2H2 upon contact with water/moisture the assessment is based on the degradation products. For details please refer to the read across report in section 13.
- Reason / purpose for cross-reference:
- read-across source
- Key result
- H:
- 116 900 Pa m³/mol
- Temp.:
- 25 °C
- Atm. press.:
- 1 013 hPa
- Conclusions:
- The calculated Henry Law Constant for acetylene is ~ 116,900 Pa m³/mol.
- Executive summary:
The vapour pressure of acetylene was calculated from the substances water solubility (1200 mg/L = 46.08 mol/m³) and its vapour pressure (4.04 x 10^4 mm Hg at 25 °C = 5386224 Pa). Thus the approximate Henry Law constant is : H = vapour pressure/ aqueous solubility = 5386224 Pa / 46.08 mol/m³ = ~ 116,900 Pa m³/mol.
This information is used in a read-across approach in the assessment of the target substance. For justification of read-across please refer to the read-across report attached to IUCLID section 13.
Reference
Description of key information
The calculated Henry Law constant of acetylene based on the substances water solubility and vapour pressuer is 116,900 Pa m³/mol.
Key value for chemical safety assessment
- Henry's law constant (H) (in Pa m³/mol):
- 116 900
- at the temperature of:
- 25 °C
Additional information
CaC2 instantly hydrolyses to the decomposition products Ca(OH)2 and C2H2 upon contact with water. Therefore, the assessment is based on these decomposition products. As the vapour pressure of Ca(OH)2 is negligible, the Henry Law constant has only been calculated for acetylene.
The vapour pressure of acetylene was calculated from the substances water solubility (1200 mg/L = 46.08 mol/m³) and its vapour pressure (4.04 x 10^4 mm Hg at 25 °C = 5386224 Pa). Thus the approximate Henry Law constant is : H = vapour pressure/ aqueous solubility = 5386224 Pa / 46.08 mol/m³ = ~ 116,900 Pa m³/mol
This information is used in a read-across approach in the assessment of the target substance. For justification of read-across please refer to the read-across report attached to IUCLID section 13.
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.
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