ASTM E200-23

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: E200 − 23
Standard Practice for
Preparation, Standardization, and Storage of Standard and
Reagent Solutions for Chemical Analysis
This standard is issued under the fixed designation E200; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope* responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
1.1 This practice covers procedures for the preparation,
mine the applicability of regulatory limitations prior to use.
standardization, and storage of the standard volumetric solu-
Specific warning statements are given throughout this practice.
tions and reagent testing solutions commonly used in chemical
Consult current OSHA regulations, suppliers’ Safety Data
analysis.
Sheets, and local regulations for all materials used in this
1.2 The information in this practice is arranged as follows:
specification.
Sections
1.5 This international standard was developed in accor-
Referenced Documents 2
dance with internationally recognized principles on standard-
Terminology 3
ization established in the Decision on Principles for the
Significance and Use 4
Apparatus 5
Development of International Standards, Guides and Recom-
Temperature effects 6
mendations issued by the World Trade Organization Technical
Measurements 7
Barriers to Trade (TBT) Committee.
Reagents 8
Concentration of solutions 9
Mixing of solutions 10
2. Referenced Documents
Storage of solutions 11
Preparation and standardization of solutions 12
2.1 ASTM Standards:
Precision and Bias 13
D1193 Specification for Reagent Water
Sodium hydroxide solution, 0.02 to 1.0 meq/mL (N) 14 to 19
E50 Practices for Apparatus, Reagents, and Safety Consid-
Hydrochloric acid, 0.02 to 1.0 meq/mL (N) 20 to 28
Sulfuric acid, 0.02 to 1.0 meq/mL (N) 29 to 33
erations for Chemical Analysis of Metals, Ores, and
Hydrochloric acid, special 1 meq/mL (N) 34 to 38
Related Materials
Sulfuric acid, special 1 meq/mL (N) 39 to 43
E180 Practice for Determining the Precision of ASTM
Silver nitrate solution, 0.1 meq/mL (N) 44 to 48
Ammonium thiocyanate solution, 0.1 meq/mL (N) 49 to 53
Methods for Analysis and Testing of Industrial and Spe-
Iodine solution, 0.1 meq/mL (N) 54 to 58 3
cialty Chemicals (Withdrawn 2009)
Sodium thiosulfate solution, 0.1 meq/mL (N) 59 to 63
E203 Test Method for Water Using Volumetric Karl Fischer
Potassium permanganate solution, 0.1 meq/mL (N) 64 to 68
Potassium dichromate solution, 0.1 meq/mL(N) 69 to 73
Titration
Methanolic sodium hydroxide solution, 0.5 meq/mL (N) 74 to 79
E694 Specification for Laboratory Glass Volumetric Appa-
Ceric sulfate solution, 0.1 meq/mL (N) 80 to 84
ratus
Acetous perchloric acid, 0.1 meq/mL (N) 85 to 89
Disodium ethylenediaminetetraacetate solution, 0.05 mol/ 90 to 94
2.2 Other Document:
L(M)
Reagent Chemicals American Chemical Society Specifica-
Standard ion solutions 95
Nonstandardized reagent solutions and indicator solutions 96 tions (ACS)
1.3 The values stated in SI units are to be regarded as
3. Terminology
standard. The values given in parentheses are for information
only. 3.1 Definitions:
1.4 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
This practice is under the jurisdiction of ASTM Committee D16 on Aromatic, Standards volume information, refer to the standard’s Document Summary page on
Industrial, Specialty and Related Chemicals and is the direct responsibility of the ASTM website.
Subcommittee D16.04 on Instrumental Analysis. The last approved version of this historical standard is referenced on
Current edition approved July 1, 2023. Published July 2023. Originally approved www.astm.org.
in 1962 as E200 – 62T. Last previous edition approved in 2016 as E200 – 16. DOI: Available from American Chemical Society (ACS), 1155 Sixteenth St., NW,
10.1520/E0200-23. Washington, DC 20036, http://www.acs.org.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E200 − 23
3.1.1 standard volumetric solution—a solution of accurately where:
determined concentration used in the quantitative analysis of
N = meq/mL (N) of solution when standardized,
t1
chemicals and other products. The concentration of such
N = meq/mL (N) of solution when used,
t2
solutions is usually expressed in terms of meq/mL (N) normal- t = temperature of solution during standardization,°C
ity or mol/L (M) molarity. t = temperature of solution during use, °C, and
F = factor to correct for thermal expansion of the solution
(ΔN/°C values from Table 1).
4. Significance and Use
4.1 The accuracy of many analytical measurements is de- 6.2 From the above equation it will be seen that the
correction is to be added to the meq/mL (N) of the solution
pendent upon the manner in which the standard solutions are
prepared and stored, and the accuracy with which they are when standardized if the temperature of use is lower than the
temperature of standardization while the correction is to be
standardized. Combining the methods recommended for the
preparation and handling of such solutions into one practice subtracted if the temperature of use is higher than the tempera-
ture of standardization.
eliminates the necessity for covering such details in all of the
methods wherein the solutions are used.
7. Measurements
5. Apparatus
7.1 Weighings—When it is directed that a chemical should
be “accurately weighed,” the weighing is to be performed in a
5.1 Volumetric Glassware—The use of ordinary volumetric
manner so as to limit the error to 0.1 % or less. Where a
glassware will meet the accuracy requirements of many test
specific weight of substance is designated in a procedure, it is
methods.
intended, unless otherwise specified in the individual
NOTE 1—For dependable accuracy, volumetric glassware meeting the
procedure, that a quantity within 65 % of the designated
requirements for Class A items given in Specification E694 should be
weight be used, and that this quantity be “accurately weighed”
used. While for normal work apparatus meeting these specifications can be
as just defined.
used without calibration corrections, it is preferable that such calibration
corrections be used in standardizing volumetric solutions. Such correc-
NOTE 2—In weighing primary standards to be used in standardizing
tions may be of significance when the volumetric ware is frequently used
volumetric solutions many laboratories customarily weigh to the nearest
with alkali solutions, for the corrosive effect of the alkali upon the glass
0.1 mg even though such increased accuracy of weighing does not
may result in changes in the apparent volume. It is recommended,
improve the accuracy or precision of the standardization.
therefore, that volumetric glassware, particularly burets and transfer
pipets, be recalibrated at 3-month intervals if it is frequently used to
7.2 Buret Readings—When buret readings are specified, or
measure alkali solution volumes.
when the procedure infers that a specific volume be measured
5.2 Buret—A 50 mL buret, or alternatively, a 100 mL buret from a buret, the reading is to be estimated to one fifth of the
with a 50 mL bulb at the top and a 50 mL stem below, may be
smallest volume subdivision marked on the buret. In reading a
used. For use with alkali solutions, burets equipped with 50 mL buret having subdivisions of 0.10 mL, therefore, the
TFE-fluorocarbon stopcock plugs are preferable. reading should be estimated to the nearest 0.02 mL.
7.3 Expression of Results—It is recommended to express the
6. Temperature Effects
concentration of the solutions as the normality in the equivalent
6.1 Volumetric solutions are often used at temperatures
SI units as meq/mL (N) and molarity as mol/L (M).
differing from those at which the standardization was carried
8. Reagents
out. Significant errors may be introduced when the solutions
NOTE 3—Additional information on reagents is given in Practices E50.
are used at these other temperatures. Values for the change of
normality with temperature (ΔN/°C) have been established for 8.1 Purity of Reagents—Reagent grade chemicals shall be
the volumetric solutions described herein, and are listed in
used in all tests. Unless otherwise indicated, it is intended that
Table 1. When warranted by the desired accuracy of the work, all reagents conform to the specifications of the Committee on
normalities of standard solutions may be corrected to the
Analytical Reagents of the American Chemical Society where
temperature at which they are used as follows: such specifications are available. Other grades may be used,
provided it is first ascertained that the reagent is of sufficiently
N 5 N 1 t 2 t ~F! (1)
~ !
t2 t1 1 2
high purity to permit its use without lessening the accuracy of
the determination.
8.2 Purity of Water—Unless otherwise indicated, references
TABLE 1 Temperature Correction Factors (F)
to water shall be understood to mean Type I or Type II reagent
Approximate ΔN/°C for 20
water conforming to Specification D1193. Where specified,
Solute
meq/mL (N) to 30 °C
carbon dioxide-free water is to be prepared by heating Type I
1.0 NaOH, HCl, H SO 0.00035
2 4
0.5 NaOH, HCl, H SO 0.00014
2 4
0.1 all aqueous 0.00002
ACS Reagent Chemicals, Specifications and Procedures for Reagents and
0.05 all aqueous 0.00001
Standard-Grade Reference Materials, American Chemical Society, Washington,
0.01 all aqueous 0.00000
DC. For suggestions on the testing of reagents not listed by the American Chemical
0.5 (in methanol) NaOH 0.00045
Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset,
0.1 (in 1 N H SO ) Ce(SO ) 0.000035
2 4 4 2
0.1 (in glacial acetic acid) HClO 0.00011 U.K., and the United States Pharmacopeia and National Formulary, U.S. Pharma-
copeial Convention, Inc. (USPC), Rockville, MD.
E200 − 23
or Type II water to boiling in a conical flask, and boiling for 20 12. Preparation and Standardization of Solutions
min. The boiling water is cooled in the flask which is stoppered
12.1 Methods of standardization are given for each volu-
with a 1-hole rubber stopper fitted to a soda lime-ascarite
metric solution even though the methods of preparation for
drying tube. For larger (10 L to 20 L) volumes of carbon
some of these solutions specify that they be prepared on a
dioxide-free water, the absorbed carbon dioxide may be re-
determinate basis. Since it is not possible to prepare large
moved by inserting a fritted-glass gas-dispersion tube to the
volumes of solutions on a determinate basis, a method of
bottom of the container and bubbling nitrogen through the
standardization is provided for those solutions that are prepared
water for 1 or 2 h.
in such large volumes that accurate measurements of the
solution volumes cannot be made.
8.3 Primary Standards—Use either independently prepared
or commercially available certified reference materials.
13. Precision and Bias
9. Concentration of Solutions
13.1 Precision—Precision for standardizing the volumetric
solutions in this practice was determined in accordance with
9.1 Standard Solutions—Directions are given for the prepa-
Practice E180 – 90 and the forms of the statements conform
ration of the most commonly used concentrations of the
with that suggested in Practice E180 – 90.
standard volumetric solutions. Stronger or weaker solutions are
prepared and standardized in the same general manner as 13.2 Bias—No information concerning the bias of these
described, using proportionate amounts of the reagents. standardization methods is available because certified refer-
Similarly, if quantities larger than 1 L are to be prepared, ence solutions suitable for this practice are not available.
proportionate amounts of the reagents should be used.
STANDARD VOLUMETRIC SOLUTIONS
9.2 Diluted Acids and Ammonium Hydroxide—
SODIUM HYDROXIDE SOLUTION,
Concentrations of diluted acids and ammonium hydroxide,
0.02 TO 1.0 meq/mL N
except when standardized, shall be specified as a ratio stating
the number of volumes of the concentrated reagent to be
14. Preparation of 50 % NaOH Solution and of Standard
diluted with a given number of volumes of water, as in the
Solutions
following example: HCl (5 + 95) means 5 volumes of concen-
14.1 Dissolve 162 g of sodium hydroxide (NaOH) in
trated HCl (sp gr 1.19) diluted with 95 volumes of water.
150 mL of carbon dioxide-free water. Cool the solution to
25 °C and filter through a hardened filter paper or other suitable
10. Mixing of Solutions
medium. Alternatively, commercial 50 % NaOH solution may
be used.
10.1 When quantities of solution larger than 1 L to 2 L are
prepared, special problems are encountered in being sure that
14.2 To prepare a 0.1 meq/mL (N) solution, dilute 5.45 mL
they are well mixed before being standardized. While blade
of the clear solution to 1 L with carbon dioxide-free water, mix
stirrers with glass or metal shafts are suitable for many
well, and store in a tight polyolefin container.
solutions, they are not suitable in every case. In those cases
14.3 For other normalities of NaOH solution, use the
where contact of a glass or metal stirrer with the solution would
requirements given in Table 2.
be undesirable it may be possible to use a sealed polyolefin-
coated stirrer. In those cases where only contact of the solution
with metal must be avoided, the solution can be mixed by
inserting a fritted-glass gas-dispersion tube to the bottom of the
TABLE 2 Sodium Hydroxide Dilution Requirements
container and bubbling nitrogen through the solution for 1 or
2 h. Volume of 50 % NaOH
Desired Grams of NaOH Solution (25°C)
meq/mL (N) Required/1 L of Solution Required/1 L of
11. Storage of Solutions
Solution, mL
0.02 0.8 1.1
11.1 Glass containers are suitable for the storage of most of
0.04 1.6 2.2
the standard solutions, although the use of polyolefin contain-
0.05 2.0 2.7
0.1 4.0 5.4
ers is recommended for alkali solutions.
0.2 8.0 10.9
0.25 10.0 13.6
11.2 When large quantities of solutions are prepared and
0.5 20.0 27.2
standardized, it is necessary to provide protection against
1.0 40.0 54.5
changes in standardization concentration due to absorption of
gases or water vapor from the laboratory air. As volumes of
solution are withdrawn from the container, the replacement air
should be passed through a drying tube filled with equal parts
of 8 to 20-mesh soda lime, oxalic acid, and 4 to 8-mesh
anhydrous calcium chloride, each product being separated
Supporting data have been filed at ASTM International Headquarters and may
from the other by a glass wool plug or use equivalent
be obtained by requesting Research Report RR:E15-1039. Contact ASTM Customer
commercially available absorption tubes. Service at service@astm.org.
E200 − 23
15. Standardization solution must be standardized frequently if there is evidence of
action on the glass container, or if insoluble matter appears in
15.1 Crush 10 g to 20 g of primary standard potassium
the solution.
hydrogen phthalate (KHC H O ) to 100-mesh fineness, and
8 4 4
dry in a glass container at 120 °C for 2 h. Stopper the container
19. Precision and Bias
and cool in a desiccator.
19.1 The following criteria should be used for judging the
15.2 To standardize a 0.1 meq/mL (N) solution, weigh
accurately 0.95 g 6 0.05 g of the dried KHC H O , and acceptability of results:
8 4 4
transfer to a 500 mL conical flask. Add 100 mL of carbon 19.1.1 Sodium Hydroxide (1.0 meq/mL (N)) (See Note 5):
dioxide-free water, stir gently to dissolve the sample, add 3
19.1.1.1 Repeatability (Single Analyst)—The standard de-
drops of a 1.0 % solution of phenolphthalein in alcohol, and
viation for a single determination has been estimated to be
titrate with NaOH solution to a color that matches that of an
0.0007 meq/mL (N) normality units at 36 df. The 95 % limit for
end point color standard.
the difference between two such determinations is 0.0020
15.3 The weights of dried KHC H O suitable for other meq/mL (N) normality units.
8 4 4
normalities of NaOH solution are given in Table 3.
19.1.1.2 Laboratory Precision (Within-Laboratory,
Between-Days Variability)—The standard deviation of results
(each the average of duplicates) obtained by the same analyst
TABLE 3 Weights of Dried Potassium Hydrogen Phthalate
on different days, has been estimated to be 0.0007 meq/mL (N)
Weight of Dried
normality units at 18 df. The 95 % limit for the difference
meq/mL (N) of Solution
A
KHC H O to Be Used, g
8 4 4
between two such averages is 0.0020 meq/mL (N) normality
0.02 0.19 ± 0.005
units.
0.04 0.38 ± 0.005
0.05 0.47 ± 0.005
19.1.1.3 Reproducibility (Multilaboratory)—The standard
0.1 0.95 ± 0.05
deviation of results (each the average of duplicates), obtained
0.2 1.90 ± 0.05
by analysts in different laboratories, has been estimated to be
0.25 2.35 ± 0.05
0.5 4.75 ± 0.05
0.001 meq/mL (N) normality units at 17 df. The 95 % limit for
1.0 9.00 ± 0.05
the difference between two such averages is 0.0028 meq/mL
A
The listed weights are for use when a 50 mL buret is to be used. If a 100 mL buret
(N) normality units.
is to be used, the weights should be doubled.
19.1.2 Sodium Hydroxide (0.1 meql/mL (N)):
19.1.2.1 Repeatability (Single Analyst)—The standard de-
viation for a single determination has been estimated to be
16. pH 8.6 End Point Color Standard
0.00009 meq/mL (N) normality units at 28 df. The 95 % limit
for the difference between two such determinations is 0.0003
16.1 Mix 25 mL of a solution 0.2 mol/L (M) in boric acid
meq/mL (N) normality units.
(H BO ) and 0.2 mol/L (M) in potassium chloride (KCl),
3 3
(1.24 g H BO and 1.49 KCl in 100 mL water) with 12 mL of 19.1.2.2 Laboratory Precision (Within-Laboratory,
3 3
0.1 N NaOH solution, add 3 drops of a 1.0 % solution of
Between-Days Variability)—The standard deviation of results
phenolphthalein in alcohol, and dilute to 100 mL with carbon (each the average of duplicates) obtained by the same analyst
dioxide-free water.
on different days, has been estimated to be 0.00011 meq/mL
(N) normality units at 14 df. The 95 % limit for the difference
17. Calculation
between two such averages is 0.0003 meq/mL (N) normality
units.
17.1 Calculate the meq/mL (N) of the NaOH solution, as
follows:
19.1.2.3 Reproducibility (Multilaboratory)—The standard
deviation of results (each the average of duplicates), obtained
B
A 5 (2)
by analysts in different laboratories, has been estimated to be
0.20423 × C
0.00020 meq/mL (N) at 13 df. The 95 % limit for the difference
where:
between two such averages is 0.0005 meq/mL (N) normality
A = meq/mL (N) of the NaOH solution,
units.
B = grams of KHC H O used, and
8 4 4
C = millilitres of NaOH solution consumed. NOTE 4—Precision data have not been obtained for concentrations other
than those listed.
18. Stability NOTE 5—These precision estimates are based on an interlaboratory
study conducted in 1962. One sample was analyzed. One analyst in each
18.1 The use of polyolefin containers eliminates some of the
of 18 laboratories performed duplicate determinations and repeated them
difficulties attendant upon the use of glass containers, and their
on a second day, for a total of 72 determinations. Practice E180 was used
use is recommended. Should glass containers be used, the in developing these statements.
NOTE 6—These precision estimates are based on an interlaboratory
study conducted in 1962. One sample was analyzed. One analyst in each
of 16 laboratories performed duplicate determinations and repeated them
A primary standard grade of this chemical (and many others) is available from
on a second day, for a total of 64 determinations. Practice E180 was used
the Office of Standard Reference Materials, National Institute of Standards and
Technology, Gaithersburg, MD 20899. in developing these statements.
E200 − 23
TABLE 5 Weights of Dried Sodium Carbonate
HYDROCHLORIC ACID,
0.02 to 1.0 meq/mL (N) Weight of Dried
meq/mL (N) of Solution
Na CO to Be Used, g
2 3
A
20. Preparation
0.02 0.088 ± 0.001
A
0.04 0.176 ± 0.001
B
20.1 To prepare a 0.1 meq/mL (N) solution, measure 8.3 mL
0.1 0.22 ± 0.01
B
of concentrated hydrochloric acid (HCl, sp gr 1.19) into a 0.2 0.44 ± 0.01
B
0.5 1.10 ± 0.01
graduated cylinder and transfer it to a 1 L volumetric flask.
B
1.0 2.20 ± 0.01
Dilute to the mark with water, mix well, and store in a tightly
A
A 100 mL buret should be used for this standardization.
closed glass container. B
The listed weights are for use when a 50 mL buret is used. If a 100 mL buret is
to be used, the weights should be doubled.
20.2 For other normalities of HCl solution, use the require-
ments given in Table 4.
23. Stability
TABLE 4 Hydrochloric Acid Dilution Requirements
23.1 Restandardize monthly.
Volume of HCl to Be
Desired meq/mL (N)
Diluted to 1 L, mL
24. Precision and Bias (See Note 4)
0.02 1.66
0.04 3.32
24.1 The following criteria should be used for judging the
0.1 8.3
acceptability of results:
0.2 16.6
0.5 41.5
24.1.1 Hydrochloric Acid (1.0 meq/mL (N)) (See Note 5):
1.0 83.0
24.1.1.1 Repeatability (Single Analyst)—The standard de-
viation for a single determination has been estimated to be
0.0004 meq/mL (N) normality units at 36 df. The 95 % limit for
21. Standardization with Sodium Carbonate
the difference between two such determinations is 0.0011
21.1 Transfer 2 g to 4 g of primary standard anhydrous
meq/mL (N) normality units.
sodium carbonate (Na CO ) to a platinum dish or crucible, and
2 3 24.1.1.2 Laboratory Precision (Within-Laboratory,
dry at 250 °C for 4 h. Cool in a desiccator.
Between-Days Variability)—The standard deviation of results
(each the average of duplicates) obtained by the same analyst
21.2 To standardize a 0.1 meq/mL (N) solution, weigh
on different days, has been estimated to be 0.0006 meq/mL (N)
accurately 0.22 g 6 0.01 g of the dried Na CO , and transfer to
2 3
normality units at 18 df. The 95 % limit for the difference
a 500 mL conical flask. Add 50 mL of water, swirl to dissolve
between two such averages is 0.0017 meq/mL (N) normality
the carbonate, and add 2 drops of a 0.1 % solution of methyl
units.
red in alcohol. Titrate with the HCl solution to the first
24.1.1.3 Reproducibility (Multilaboratory)—The standard
appearance of a red color, and boil the solution carefully, to
deviation of results (each the average of duplicates), obtained
avoid loss, until the color is discharged. Cool to room
by analysts in different laboratories has been estimated to be
temperature, and continue the titration, alternating the addition
0.0015 meq/mL (N) normality units at 17 df. The 95 % limit for
of HCl solution and the boiling and cooling to the first
the difference between two such averages is 0.0042 meq/mL
appearance of a faint red color that is not discharged on further
(N) normality units.
heating.
24.1.2 Hydrochloric Acid (0.1 meql/mL (N)) (See Note 6):
21.3 The weights of dried Na CO suitable for other nor-
2 3
24.1.2.1 Repeatability (Single Analyst)—The standard de-
malities of HCl solution are given in Table 5.
viation for a single determination has been estimated to be
0.00010 meq/mL (N) normality units at 28 df. The 95 % limit
22. Calculation
for the difference between two such determinations is 0.0003
22.1 Calculate the normality of the HCl solution, as follows:
meq/mL (N) normality units.
B
24.1.2.2 Laboratory Precision (Within-Laboratory,
A 5 (3)
0.053 × C
Between-Days Variability), formerly called Repeatability—The
standard deviation of results (each the average of duplicates)
where:
obtained by the same analyst on different days, has been
A = meq/mL (N) normality of the HCl solution,
estimated to be 0.00007 meq/mL (N) normality units at 14 df.
B = grams of Na CO used, and
2 3
The 95 % limit for the difference between two such averages is
C = millilitres of HCl solution consumed.
0.0002 meq/mL (N) normality units.
24.1.2.3 Reproducibility (Multilaboratory)—The standard
deviation of results (each the average of duplicates), obtained
A buret having a bent delivery tube is helpful in carrying out this standardiza-
tion procedure. by analysts in different laboratories has been estimated to be
E200 − 23
0.00017 meq/mL (N) normality units at 13 df. The 95 % limit normality units at 8 df. The 95 % limit for the difference
for the difference between two such averages is 0.0005 between two such averages is 0.0020 meq/mL (N) normality
meq/mL (N) normality units. units.
28.1.1.3 Reproducibility (Multilaboratory)—The standard
25. Standardization with Tris(hydroxymethyl)-
deviation of results (each the average of duplicates), obtained
Aminomethane
by analysts in different laboratories has been estimated to be
0.0015 meq/mL (N) normality units at 7 df. The 95 % limit for
25.1 Transfer 8 g to 10 g of primary standard tris(hy-
droxymethyl)aminomethane [(HOCH ) CNH ] to a suitable the difference between two such averages is 0.0042 meq/mL
2 3 2
(N) normality units.
dish or crucible, and dry in a vacuum at 70 °C for 24 h. Cool
in a desiccator. 28.1.2 Hydrochloric Acid (0.1 meq/mL (N):
28.1.2.1 Repeatability (Single Analyst)—The standard de-
25.2 To standardize a 0.1 meq/mL (N) solution, weigh
viation for a single determination has been estimated to be
accurately 0.40 g 6 0.02 g of the dried tris(hydroxymethyl)
0.00010 meq/mL (N) normality units at 16 df. The 95 % limit
aminomethane, and transfer to a 250 mL beaker. Dissolve in
for the difference between two such determinations is 0.0003
50 mL of ammonia- and carbon dioxide-free water, and titrate
meq/mL (N) normality units.
with the HCl solution to a pH of 4.70 using a suitable pH meter.
28.1.2.2 Laboratory Precision (Within-Laboratory,
25.3 The weights of dried tris(hydroxymethyl)aminometh-
Between-Days Variability)—The standard deviation of results
ane suitable for other normalities of HCl solution are given in
(each the average of duplicates) obtained by the same analyst
Table 6.
on different days, has been estimated to be 0.00012 meq/mL
(N) normality units at 8 df. The 95 % limit for the difference
26. Calculation
between two such averages is 0.0003 meq/mL (N) normality
26.1 Calculate the meq/mL (N) normality of the HCl
units.
solution, as follows:
28.1.2.3 Reproducibility (Multilaboratory)—The standard
deviation of results (each the average of duplicates) obtained
B
A 5 (4)
by analysts in different laboratories has been estimated to be
0.1211 × C
0.00024 meq/mL (N) normality units at 7 df. The 95 % limit for
where:
the difference between two such averages is 0.0007 meq/mL
A = meq/mL (N) normality of the HCl solution,
(N) normality units.
B = grams of tris(hydroxymethyl)aminomethane used, and
C = millilitres of HCl solution consumed.
TABLE 7 Sulfuric Acid Dilution Requirements
Volume of H SO to Be
27. Stability
2 4
Desired meq/mL (N)
Diluted to 1 L, mL
27.1 Restandardize monthly.
0.02 0.60
0.1 3.0
28. Precision and Bias (See Notes 7 and 8)
0.2 6.0
0.5 15.0
28.1 The following criteria should be used for judging the
1.0 30.0
acceptability of results:
28.1.1 Hydrochloric Acid (1.0 meq/mL (N)):
28.1.1.1 Repeatability (Single Analyst)—The standard de-
NOTE 7—These precision estimates are based on an interlaboratory
viation for a single determination has been estimated to be
study conducted in 1973. One sample of each concentration was analyzed.
One analyst in each of 9 laboratories performed duplicate determinations
0.0006 meq/mL (N) normality units at 16 df. The 95 % limit for
and repeated them on a second day, for a total of 36 determinations for
the difference between two such determinations is 0.0017
each concentration herein. Practice E180 was used in developing these
meq/mL (N) normality units.
statements.
28.1.1.2 Laboratory Precision (Within-Laboratory,
NOTE 8—Precision data have not been obtained for concentrations other
Between-Days Variability)—The standard deviation of results than those listed in Section 28.
(each the average of duplicates) obtained by the same analyst
SULFURIC ACID,
on different days, has been estimated to be 0.0007 meq/mL (N)
0.02 TO 1.0 meq/mL (N)
TABLE 6 Weights of Dried Tris(Hydroxymethyl)Aminomethane
29. Preparation
Weight of Dried
meq/mL (N) of Solution
29.1 To prepare a 0.1 meq/mL (N) solution, measure 3.0 mL
(HOCH ) CNH to be Used, g
2 3 2
A of concentrated sulfuric acid (H SO , sp gr 1.84) into a
2 4
0.02 0.16 ± 0.008
A
graduated cylinder and slowly add it to 400 mL of water in a
0.04 0.32 ± 0.016
B
0.1 0.40 ± 0.02
600 mL beaker. Rinse the cylinder into the beaker with water.
B
0.2 0.80 ± 0.04
Mix the acid-water mixture, allow it to cool, and transfer to a
B
0.5 2.0 ± 0.1
B
1.0 4.0 ± 0.2 1 L volumetric flask. Dilute to the mark with water, mix well,
A
and store in a tightly closed glass container.
A 100 mL buret should be used for this standardization.
B
The listed weights are for use when a 50 mL buret is used. If a 100 mL buret is
29.2 For other meq/mL (N) normalities of the H SO
2 4
to be used, the weights should be doubled.
solution, use the requirements given in Table 7.
E200 − 23
30. Standardization 1 L volumetric flask. Dilute to the mark with water, mix well,
and store in a tightly closed glass container.
30.1 Transfer 2 g to 4 g of primary standard anhydrous
sodium carbonate (Na CO ) to a platinum dish or crucible, and
2 3
35. Standardization
dry at 250 °C for 4 h. Cool in a desiccator.
35.1 Transfer 5 g of primary standard anhydrous sodium
30.2 For standardization of a 0.1 meq/mL (N) solution,
carbonate (Na CO ) to a platinum dish or crucible, and dry at
weigh accurately 0.22 g 6 0.01 g of the dried Na CO and
2 3
2 3
250 °C for 4 h (see Table 5). Cool in a desiccator. Weigh
transfer to a 500 mL conical flask. Add 50 mL of water, swirl
accurately 2.2 g 6 0.1 g of the dried Na CO , and transfer to
to dissolve the Na CO , and add 2 drops of a 0.1 % solution of
2 3
2 3
a 500 mL conical flask. Add 75 mL of water, swirl to dissolve
methyl red in alcohol. Titrate with the H SO solution to the
2 4
the Na CO , and add 3 drops of a 0.1 % solution of methyl
first appearance of a red color, and boil the solution carefully,
2 3
orange indicator. Titrate with HCl solution to a pink color.
to avoid loss, until the color is discharged. Cool to room
temperature and continue the titration alternating the addition
35.2 Methyl orange indicator solution modified with xylene
of H SO solution and the boiling and cooling, to the first
2 4
cyanole FF, suitable for use as an alternative indicator in this
appearance of a faint red color that is not discharged on further
procedure, is described in 96.17. Titrate with HCl solution to a
heating.
magenta color.
30.3 The weights of dried Na CO suitable for other
2 3
meq/mL (N) normalities of H SO solution are given in Table
2 4 36. Calculation
5.
36.1 Calculate the meq/mL (N) normality of the HCl
solution, as follows:
31. Calculation
B
31.1 Calculate the meq/mL (N) normality of the H SO
2 4
A 5 (6)
0.053 × C
solution, as follows:
B where:
A 5 (5)
0.053 × C
A = meq/mL (N) normality of the HCl solution,
B = grams of Na CO used, and
2 3
where:
C = millilitres of HCl solution consumed.
A = meq/mL (N) normality of the H SO solution,
2 4
B = grams of Na CO used, and
2 3
37. Stability
C = millilitres of H SO solution consumed.
2 4
37.1 Restandardize monthly.
32. Stability
38. Precision and Bias (See Note 11)
32.1 Restandardize monthly.
38.1 The following criteria should be used for judging the
NOTE 9—A solution of 0.1 meq/mL (N) sulfuric acid may be standard-
acceptability of results:
ized using dried tris(hydroxymethyl)aminomethane by the same procedure
used to standardize 0.1 meq/mL (N) hydrochloric acid in Section 25.
38.1.1 Repeatability (Single Analyst)—The standard devia-
tion for a single determination has been estimated to be
33. Precision and Bias
0.00064 meq/mL (N) normality units at 34 df. The 95 % limit
33.1 The following criteria should be used for judging the
for the difference between two such determinations is 0.0018
acceptability of results:
meq/mL (N) normality units.
33.1.1 Sulfuric Acid (1.0 meq/mL (N)):
38.1.2 Laboratory Precision (Within-Laboratory, Between-
33.1.1.1 Repeatability (Single Analyst)—See 24.1.1.1.
Days Variability)—The standard deviation of results (each the
33.1.1.2 Laboratory Precision (Within-Laboratory,
average of duplicates) obtained by the same analyst on
Between-Days Variability)—See 24.1.1.2.
different days, has been estimated to be 0.00081 meq/mL (N)
33.1.1.3 Reproducibility (Multilaboratory)—See 24.1.1.3.
normality units at 18 df. The 95 % limit for the difference
33.1.2 Sulfuric Acid (0.1 meq/mL (N)):
between two such averages is 0.0023 meq/mL (N) normality
33.1.2.1 Repeatability (Singly Analyst)—See 24.1.2.1.
units.
33.1.2.2 Laboratory Precision (Within-Laboratory,
38.1.3 Reproducibility (Multilaboratory)—The standard de-
Between-Days Variability)—See 24.1.2.2.
viation of results (each the average of duplicates), obtained by
33.1.2.3 Reproducibility (Multilaboratory)—See 24.1.2.3.
analysts in different laboratories has been estimated to be
0.0022 meq/mL (N) normality units at 16 df. The 95 % limit for
HYDROCHLORIC ACID, SPECIAL 1 meq/mL (N)
the difference between two such averages is 0.0062 meq/mL
NOTE 10—This solution is not for general use but is designed to satisfy
the special requirements of ASTM Committee E15, Subcommittee E15.52 (N) normality units.
on Alkalies.
NOTE 11—These precision estimates are based on an interlaboratory
study conducted in 1962. One sample was analyzed. One analyst in each
34. Preparation
of 18 laboratories performed duplicate determinations and repeated them
34.1 Measure 83.0 mL of concentrated hydrochloric acid
on a second day, for a total of 72 determinations. Practice E180 was used
(HCl, sp gr 1.19) into a graduated cylinder and transfer it to a in developing these statements.
E200 − 23
solution carefully to volume.
SULFURIC ACID, SPECIAL 1 meq/mL (N)
(See Note 10)
45. Standardization
39. Preparation
45.1 Warning—Nitrobenzene, used in this section, is ex-
39.1 Measure 30.0 mL of concentrated sulfuric acid
tremely hazardous when absorbed through the skin or when its
(H SO , sp gr 1.84) into a graduated cylinder, and slowly add vapor is inhaled. Such exposure may cause cyanosis; pro-
2 4
it to one half the desired volume of water in a 600 mL beaker.
longed exposure may cause anemia. Do not get in eyes, on
Rinse the cylinder into the beaker with water. Mix the skin, or on clothing. Avoid breathing vapor. Use only with
acid-water mixture, allow it to cool, and transfer to a 1 L
adequate ventilation.
volumetric flask. Dilute to the mark with water, mix well, and
45.2 Dry 0.3 g of sodium chloride (NaCl) at 105 °C for 2 h.
store in a tightly closed glass container.
Cool in a desiccator. Weigh accurately 0.28 g 6 0.01 g of the
dried NaCl and transfer to a 250 mL glass-stoppered conical
40. Standardization
flask. Add 25 mL of water, swirl to dissolve the NaCl, and add
40.1 Transfer 5 g of primary standard anhydrous sodium
2 mL of nitric acid (HNO ). Add from a volumetric pipet,
carbonate (Na CO ) to a platinum dish or crucible, and dry at
2 3
50 mL of the AgNO solution, while mixing thoroughly, add
250 °C for 4 h (see Table 5). Cool in a desiccator. Weigh
1 mL of ferric ammonium sulfate solution
accurately 2.2 g 6 0.1 g of the dried Na CO , and transfer to
2 3
(FeNH (SO ) ·12H O, 80 g ⁄L) and 5 mL of nitrobenzene
4 4 2 2
a 500 mL conical flask. Add 75 mL of water, swirl to dissolve
(Warning—see 45.1). Stopper the flask and shake vigorously
the Na CO , and add 3 drops of a 0.1 % solution of methyl
2 3
to coagulate the precipitate. Rinse the stopper into the flask
orange. Titrate with H SO solution to a pink color.
2 4
with a few millilitres of water and titrate the excess of AgNO
40.2 Methyl orange indicator solution modified with xylene with ammonium thiocyanate solution (NH SCN) until the first
permanent reddish-brown color appears and persists after
cyanole FF, suitable for use as an alternative indicator in this
vigorous shaking for 1 min. See 49.1 for preparation of
procedure, is described in 96.17. Titrate with H SO solution to
2 4
ammonium thiocyanate. Solution does not need to be standard-
a magenta color.
ized for use here. (See Note 13.) Designate the volume of
41. Calculation
NH SCN solution required for the titration as Volume I.
41.1 Calculate the meq/mL (N) normality of the H SO
45.3 Using the same volumetric pipet used in 45.2, transfer
2 4
solution, as follows:
50 mL of the AgNO solution to a clean, dry, 250 mL,
glass-stoppered conical flask. Add 25 mL of water, 2 mL of
B
A 5 (7)
HNO , 1 mL of FeNH (SO ) ·12H O solution, stopper the
0.053 × C 3 4 4 2 2
flask, and shake vigorously. Rinse the stopper into the flask
where:
with a few millilitres of water and titrate the AgNO solution
A = meq/mL (N) normality of the H SO solution,
2 4 with NH SCN solution until the first permanent reddish-brown
B = grams of Na CO used, and
2 3
color appears and persists after vigorous shaking for 1 min.
C = millilitres of H SO solution consumed.
2 4
Designate the volume of NH SCN solution consumed as
Volume II.
42. Stability
45.4 Measure accurately, from either a buret or a volumetric
42.1 Restandardize monthly.
pipet, 2.0 mL of the AgNO solution, designate the exact
volume as Volume III, and transfer to a 100 mL, glass-
43. Precision and Bias
stoppered conical flask. Add 25 mL of water, 2 mL of HNO ,
43.1 The following criteria should be used for judging the
1 mL of FeNH (SO ) ·12H O solution, and 5 mL of
4 4 2 2
acceptability of results:
nitrobenzene, (Warning—see 45.1) stopper the flask, and
43.1.1 Repeatability (Single Analyst)—See 38.1.1.
shake vigorously. Rinse the stopper into the flask with a few
43.1.2 Laboratory Precision (Within-Laboratory, Between-
millilitres of water and titrate the AgNO solution with
Days Variability)—See 38.1.2.
NH SCN solution until the first permanent reddish-brown
43.1.3 Reproducibility (Multilaboratory)—See 38.1.3.
color appears and persists after vigorous shaking for 1 min.
Designate the volume of NH SCN solution consumed as
SILVER NITRATE SOLUTION,
Volume IV.
0.1 meq/mL (N)
NOTE 13—The ammonium thiocyanate titrant used in the three titrations
44. Preparation
must be from the same, well-mixed solution. The nitrobenzene used in
each titration must also be from the same, well-mixed container.
44.1 Dry 17.5 g of silver nitrate (AgNO ) at 105 °C for 1 h.
Cool in a desiccator. Transfer 16.99 g of the dried AgNO to a
46. Calculation
1 L volumetric flask. Add 500 mL of water, swirl to dissolve
46.1 Calculate the meq/mL (N) normality of the AgNO
the AgNO , dilute to the mark with water, and mix. Store the
solution as follows:
solution in a tightly stoppered amber-glass bottle.
B
NOTE 12—If desired the solution may also be prepared on a determinate
A 5 (8)
basis by weighing the dried silver nitrate accurately and diluting the 0.05844 × C 2 D
~ !
E200 − 23
where: 51. Calculation
A = meq/mL (N) normality of the AgNO solution,
3 51.1 Calculate the meq/mL (N) normality of the NH SCN
B = grams of NaCl used,
solution, as follows:
C = volume of AgNO solution consumed by the total
B × C
chloride = 50 − [Volume I × (50 ⁄Volume II)], an
A 5 (9)
D
D = volume of AgNO solution consumed by any chloride
ion in the nitrobenzene = Volume III − [Volume
where:
IV × (50 ⁄Volume II)].
A = meq/mL (N) normality of the NH SCN solution,
B = millilitres of AgNO used,
47. Stability
C = meq/mL (N) normality of the AgNO solution, and
47.1 Restandardize monthly. D = millilitres of NH SCN solution required for titration of
the solution.
48. Precision and Bias (See Note 14)
52. Stability
48.1 The following criteria should be used for judging the
acceptability of results:
52.1 Restandardize monthly.
48.1.1 Repeatability (Single Analyst)—The standard devia-
53. Precision and Bias (See Note 14)
tion for a single determination has been estimated to be
0.00010 meq/mL (N) normality units at 34 df. The 95 % limit
53.1 The following criteria should be used for judging the
for the difference between two such determinations is 0.0003
acceptability of results:
meq/mL (N) normality units.
53.1.1 Repeatability (Single Analyst)—The standard devia-
48.1.2 Laboratory Precision (Within-Laboratory, Between-
tion for a single determination has been estimated to be
Days Variability)—The standard deviation of results (each the
0.00010 meq/mL (N) normality units at 38 df. The 95 % limit
average of duplicates) obtained by the same analyst on
for the difference between two such determinations is 0.00028
different days, has been estimated to be 0.00017 meq/mL (N)
meq/mL (N) normality units.
normality units at 17 df. The 95 % limit for the difference
53.1.2 Laboratory Precision (Within-Laboratory, Between-
between two such averages is 0.0005 meq/mL (N) normality
Days Variability)—The standard deviation of results (each the
units.
average of duplicates) obtained by the same analyst on
48.1.3 Reproducibility (Multilaboratory)—The standard de-
different days, has been estimated to be 0.00035 meq/mL (N)
viation of results (each the average of duplicates) obtained by
normality units at 19 df. The 95 % limit for the difference
analysts in different laboratories has been estimated to be
between two such averages is 0.00099 meq/mL (N) normality
0.00035 meq/mL (N) normality units at 16 df. The 95 % limit
units.
for the difference between two such averages is 0.0010
53.1.3 Reproducibility (Multilaboratory)—The standard de-
meq/mL (N) normality units.
viation of results (each the average of duplicates), obtained by
analysts in different laboratories has been estimated to be
NOTE 14—These precision estimates are based on an interlaboratory
0.00046 meq/mL (N) normality units at 18 df. The 95 % limit
study conducted in 1963. One sample was analyzed. One analyst in each
of 19 laboratories performed duplicate determinations and repeated them
for the difference between two such averages is 0.00130
on a second day, for a total of 76 determinations. Practice E180 was used
meq/mL (N) normality units.
in developing these statements.
IODINE SOLUTION,
AMMONIUM THIOCYANATE SOLUTION,
0.1 meq/mL (N)
0.1 meq/mL (N)
54. Preparation
49. Preparation
54.1 Transfer 12.7 g of iodine and 60 g of potassium iodide
49.1 Transfer 7.8 g of ammonium thiocyanate (NH SCN) to
(KI) to an 800 mL beaker, add 30 mL of water, and stir until
a flask, add 100 mL of water, and swirl to dissolve the
solution is complete. Dilute with water to 500 mL, and filter
NH SCN. When solution is complete, filter through a hardened
through a sintered-glass filter. Wash the filter with about 15 mL
filter paper, or other suitable medium. Dilute the clear filtrate to
of water, transfer the combined filtrate and washing to a 1 L
1 L with water and mix. Store the solution in a tightly
volumetric flask, dilute to the mark with water, and mix. Store
stoppered glass bottle.
the solution in a glass-stoppered, amber-glass bottle in a cool
place.
50. Standardization
50.1 Measure accurately about 40 mL of freshly standard-
55. Standardization
ized 0.1 meq/mL (N) silver nitrate (AgNO ) solution and
55.1 Warning—Arsenic trioxide is extremely toxic, avoid
transfer to a 250 mL conical flask. Add 50 mL of water, swirl
ingestion.
to mix the solution, and add 2 mL of nitric acid (HNO ) and
1 mL ferric ammonium sulfate solution (FeNH (SO ) ·12H O, 55.2 Transfer 1 g of primary standard arsenic trioxide
4 4 2 2
80 g/L). Titrate the AgNO solution with the NH SCN solution (As O ) (Warning—see 55.1) to a platinum dish, and dry at
3 4 2 3
until the first permanent reddish-brown color appears and 105 °C for 1 h. Cool in a desiccator. Weigh accurately 0.20 g 6
persists after vigorous shaking for 1 min. 0.01 g of the dried As O and t
...