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Physical & Chemical properties

pH

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Administrative data

Endpoint:
pH
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2008-11-10 to 2008-12-19
Reliability:
1 (reliable without restriction)
Cross-referenceopen allclose all
Reason / purpose for cross-reference:
reference to other study
Reference
Endpoint:
viscosity
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2008-11-10 to 2008-12-19
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
test procedure in accordance with national standard methods
Qualifier:
according to guideline
Guideline:
OECD Test Guideline 114 (Viscosity of Liquids)
Deviations:
no
Qualifier:
according to guideline
Guideline:
other: DIN 53019
Deviations:
no
GLP compliance:
yes (incl. QA statement)
Type of method:
rotational viscometer (dynamic)
Key result
Temp.:
20°C
Parameter:
dynamic viscosity (in mPa s)
Value:
0.016
Temp.:
40°C
Parameter:
dynamic viscosity (in mPa s)
Value:
0.009
Temp.:
20°C
Parameter:
other: m2/s
Value:
0
Remarks on result:
other: The correct value of the kinematic viscosity at 20°C is 1.28 exp.-05 m2/s.

The kinematic viscosity at 40°C is 6.8 exp.-06 m2/s. An entry of this value was not possible (max. 5 decimal places are allowed and "exp. writing" is not possible.

Conclusions:
The determination of the dynamic viscosity was performed according to DIN 53019 (German industry norm) and OECD 114 using a rotary viscosimeter at 20°C and 40°C. The kinematic viscosity was calculated with the dynamic viscosity and the density at test temperature. The following results were obtained:
Dynamic viscosity at 20 °C: 1.63 E-02 Pa · s
Dynamic viscosity at 40 °C: 8.6 E-03 Pa · s
Kinematic viscosity at 20 °C: 1.28 E-05 m2/s
Kinematic viscosity at 40 °C: 6.8 E-06 m2/s
Executive summary:

The determination of the dynamic viscosity was performed according to DIN 53019 (German industry norm) and OECD 114 using a rotary viscosimeter at 20°C and 40°C. The kinematic viscosity was calculated with the dynamic viscosity and the density at test temperature. The following results were obtained for the 50.4% aqueous solution of2-phosphonobutane-1,2,4-tricarboxylic acid:


Dynamic viscosity at 20 °C: 1.63 E-02 Pa · s


Dynamic viscosity at 40 °C: 8.6 E-03 Pa · s


Kinematic viscosity at 20 °C: 1.28 E-05 m2/s


Kinematic viscosity at 40 °C: 6.8 E-06 m2/s

Reason / purpose for cross-reference:
reference to other study
Reference
Endpoint:
dissociation constant
Type of information:
calculation (if not (Q)SAR)
Adequacy of study:
key study
Study period:
2009
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
accepted calculation method
Reason / purpose for cross-reference:
reference to other study
Principles of method if other than guideline:
No experimental determination but calculation of pKa.
GLP compliance:
no
Dissociating properties:
yes
No.:
#1
pKa:
>= 8.09 - <= 9.09
Temp.:
20 °C
Remarks on result:
other: pKa (HL/H+L)
No.:
#2
pKa:
>= 4.85 - <= 5.04
Temp.:
20 °C
Remarks on result:
other: pKa (H2L/H+HL)
No.:
#3
pKa:
>= 4.34 - <= 4.54
Temp.:
20 °C
Remarks on result:
other: pKa (H3L/H+H2L)
No.:
#4
pKa:
>= 3.78 - <= 4.2
Temp.:
20 °C
Remarks on result:
other: pKa (H4L/H+H3L)
No.:
#5
pKa:
>= 0.66 - <= 1.5
Temp.:
20 °C
Remarks on result:
other: pKa (H5L/H+H4L)

Statistical factors: +/-0.30

Conclusions:
In total, 2-phosphonobutane-1,2,4-tricarboxylic acid can release 5 protons step by step. Each release is described by one equilibrium constant (pKa). Depending on the value, the acid dissociation constants (pKa values) indicate strong (#5), medium strong (#4, #3, #2) and weak (#1) acids.
The pKa values indicate neither very strong nor very weak acids.
Executive summary:

The calculation of the dissociation constants of 2-phosphonobutane-1,2,4-tricarboxylic acid in water was performed by software ACD ChemSketch ACD/Labs 7.00 Release, Product Version 7.05. Usually the resulting dissociation constants are calculated for 20°C.

2-phosphonobutane-1,2,4-tricarboxylic acid in water can release 5 protons step by step.

Each release is described by one equilibrium reaction or equilibrium constant (pKa):

H5L = H+H4L (pKa = 1.08 ± 0.42)

H4L = H+H3L (pKa = 3.99 ± 0.21)

H3L = H+H2L (pKa = 4.44 ± 0.10)

H2L = H+HL (pKa = 4.99 ± 0.14)

HL = H+L (pKa = 8.59 ± 0.50)

Depending on the pKa value, the acid dissociation constants indicate strong (pKs < 3.8), medium strong (pKs < 7.2) and weak (pKs < 16) acids.

The pKa values indicate neither very strong nor very weak acids.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2009
Report date:
2009

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
other: CIPAC MT 75.3
Deviations:
no
GLP compliance:
yes (incl. QA statement)

Test material

Constituent 1
Chemical structure
Reference substance name:
2-phosphonobutane-1,2,4-tricarboxylic acid
EC Number:
253-733-5
EC Name:
2-phosphonobutane-1,2,4-tricarboxylic acid
Cas Number:
37971-36-1
Molecular formula:
C7H11O9P
IUPAC Name:
2-phosphonobutane-1,2,4-tricarboxylic acid
Test material form:
liquid
Remarks:
aqueous solution of 2-Phosphonobutane-1,2,4-tricarboxylic acid
Details on test material:
- Name of test item: Bayhibit AM

Results and discussion

pH valueopen allclose all
Key result
pH value:
1.9
Concentration:
1 other: %
Remarks on result:
other: equals 0.5% of active ingredient (PBTC); dilution was performed with demineralised water
Key result
pH value:
0
Concentration:
100 other: %
Remarks on result:
other: equals 50.4% of active ingredient (PBTC); here it was undiluted

Applicant's summary and conclusion

Conclusions:
The determination of the pH-value was performed according to CIPAC MT 75.3. The determination of the pH value was performed with a pH meter equipped with a calibrated single-rod glass electrode. The pH-value was determined of the 50.4% aqueous solution of 2-Phosphono-1,2,4-butanetricarboxylic acid (PBTC) and of a 1 % solution of this test item (equals 0.5% PBTC) in demineralised water. The following results were received:
pH-value (1% [equals 0.5% PBTC]): 1.9
pH-value (undiluted [equals 50.4% PBTC]): 0.0
Executive summary:

The determination of the pH-value was performed according to CIPAC MT 75.3. The determination of the pH value was performed with a pH meter equipped with a calibrated single-rod glass electrode. The pH-value was determined of the 50.4% aqueous solution of 2-Phosphono-1,2,4-butanetricarboxylic acid (PBTC) and of a 1 % solution of this test item (equals 0.5% PBTC) in demineralised water. The following results were received:



pH-value (1% [equals 0.5% PBTC]): 1.9



pH-value (undiluted [equals 50.4% PBTC]): 0.0