ASTM D2710-20

Standard Test Method for Bromine Index of Petroleum Hydrocarbons by Electrometric Titration

SIGNIFICANCE AND USE
5.1 This test method provides a measure of trace amounts of unsaturated hydrocarbons in petroleum distillates boiling up to 288 °C (550 °F). An estimate of the quantity of these materials is useful in assessing the suitability of the lighter fractions for use as reaction solvents.
SCOPE
1.1 This test method covers the determination of the amount of bromine-reactive material in petroleum hydrocarbons and is thus a measure of trace amounts of unsaturates in these materials. It is applicable to materials having bromine indexes below 1000.  
1.2 This test method is applicable only to essentially olefin-free hydrocarbons or mixtures that are substantially free from material lighter than isobutane and have a distillation end point under 288 °C (550 °F).
Note 1: This procedure has been cooperatively tested on materials with bromine indexes in the range from 100 to 1000. These materials include petroleum distillates such as straight-run and hydrocracked naphtha, reformer feed, kerosine, and aviation turbine fuel.
Note 2: Materials with bromine index greater than 1000 should be tested for bromine number using Test Method D1159/IP 130.
Note 3: Bromine index of industrial aromatic hydrocarbons should be determined using Test Method D1492 or D5776. The subcommittee is currently examining ways to achieve more consistent end point values.  
1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.  
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.5 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.

General Information

• Status: Published
• Publication Date: 30-Apr-2020
• ICS: 75.100 - Lubricants, industrial oils and related products
• Technical Committee: D02 - Petroleum Products, Liquid Fuels, and Lubricants
• Drafting Committee: D02.06 - Analysis of Liquid Fuels and Lubricants

Relations

• Replaces: ASTM D2710-09(2018) - Standard Test Method for Bromine Index of Petroleum Hydrocarbons by Electrometric Titration
• Effective Date: 01-May-2020
• Refers: ASTM D1159-23 - Standard Test Method for Bromine Numbers of Petroleum Distillates and Commercial Aliphatic Olefins by Electrometric Titration
• Effective Date: 01-Nov-2023
• Refers: ASTM D5776-14 - Standard Test Method for Bromine Index of Aromatic Hydrocarbons by Electrometric Titration
• Effective Date: 15-Feb-2014
• Refers: ASTM D5776-13 - Standard Test Method for Bromine Index of Aromatic Hydrocarbons by Electrometric Titration
• Effective Date: 15-Jul-2013
• Refers: ASTM D1159-07(2012) - Standard Test Method for Bromine Numbers of Petroleum Distillates and Commercial Aliphatic Olefins by Electrometric Titration
• Effective Date: 15-Apr-2012
• Refers: ASTM D5776-07(2012) - Standard Test Method for Bromine Index of Aromatic Hydrocarbons by Electrometric Titration
• Effective Date: 01-Jan-2012
• Refers: ASTM D1492-08 - Standard Test Method for Bromine Index of Aromatic Hydrocarbons by Coulometric Titration
• Effective Date: 01-Jul-2008
• Refers: ASTM D5776-07 - Standard Test Method for Bromine Index of Aromatic Hydrocarbons by Electrometric Titration
• Effective Date: 01-Aug-2007
• Refers: ASTM D5776-07e1 - Standard Test Method for Bromine Index of Aromatic Hydrocarbons by Electrometric Titration
• Effective Date: 01-Aug-2007
• Refers: ASTM D1492-07 - Standard Test Method for Bromine Index of Aromatic Hydrocarbons by Coulometric Titration
• Effective Date: 01-Feb-2007
• Refers: ASTM D5776-99(2006) - Standard Test Method for Bromine Index of Aromatic Hydrocarbons by Electrometric Titration
• Effective Date: 01-Jun-2006
• Refers: ASTM D1492-02 - Standard Test Method for Bromine Index of Aromatic Hydrocarbons by Coulometric Titration
• Effective Date: 10-Jun-2002
• Refers: ASTM D1159-98 - Standard Test Method for Bromine Numbers of Petroleum Distillates and Commercial Aliphatic Olefins by Electrometric Titration
• Effective Date: 10-Nov-2001
• Refers: ASTM D1159-01 - Standard Test Method for Bromine Numbers of Petroleum Distillates and Commercial Aliphatic Olefins by Electrometric Titration
• Effective Date: 10-Nov-2001
• Refers: ASTM D1492-96 - Standard Test Method for Bromine Index of Aromatic Hydrocarbons by Coulometric Titration
• Effective Date: 01-Jan-2000

Overview

ASTM D2710-20 is the internationally recognized standard test method for determining the bromine index of petroleum hydrocarbons using electrometric titration. Developed by ASTM International, this method provides a reliable approach for measuring trace amounts of bromine-reactive (unsaturated) hydrocarbons in petroleum distillates with distillation endpoints under 288°C (550°F). The bromine index is a vital parameter for the assessment of product quality and suitability, especially for evaluating lighter petroleum fractions as reaction solvents.

This standard is primarily applicable to essentially olefin-free hydrocarbons or mixtures that are mostly free from materials lighter than isobutane and have a bromine index below 1000. For hydrocarbons with higher bromine indexes or industrial aromatic hydrocarbons, alternative ASTM methods are referenced.

Key Topics

• Bromine Index Determination

  • The bromine index quantifies the number of milligrams of bromine reacting with 100 grams of sample under specified test conditions.
  • It is an important indicator of the presence of unsaturated hydrocarbons (unsaturates) in petroleum products.

• Electrometric Titration Procedure

  • Uses a specialized electrometric titrator with platinum electrodes in a controlled temperature vessel.
  • The endpoint is detected by a sudden change in electrical conductivity when the sample reacts with the bromide-bromate solution.
  • Sample sizes vary depending on the estimated bromine index, ensuring precise and repeatable results.

• Applicable Sample Types

  • Straight-run and hydrocracked naphtha
  • Reformer feedstocks
  • Kerosine
  • Aviation turbine fuels

• Limitations

  • Not suitable for samples with significant olefin content or materials with a bromine index over 1000.
  • Not intended for aromatic hydrocarbons, which require other ASTM methods.

Applications

The ASTM D2710-20 test method is widely used in the petroleum and petrochemical industries for:

• Product Quality Control
  Monitoring and controlling trace unsaturate content in refining and product blending operations. This helps ensure that lighter petroleum fractions, such as naphtha and kerosine, meet quality requirements for further use.

• Solvent Suitability Assessment
  Evaluating suitability of specific petroleum distillates for use as reaction solvents in chemical processing based on their unsaturate content.

• Specification Compliance
  Meeting industry and regulatory specifications for hydrocarbon purity, especially for fuels and feedstocks that require minimal levels of unsaturated hydrocarbons.

• Research and Development
  Supporting the development and optimization of refining processes by monitoring the effectiveness of processes that reduce unsaturate levels.

Related Standards

Professionals using ASTM D2710-20 may also refer to the following related ASTM standards for specific applications or material types:

• ASTM D1159
  Standard Test Method for Bromine Numbers of Petroleum Distillates and Commercial Aliphatic Olefins by Electrometric Titration (for samples with bromine index > 1000).
• ASTM D1492
  Test Method for Bromine Index of Aromatic Hydrocarbons by Coulometric Titration (for industrial aromatic hydrocarbons).
• ASTM D5776
  Test Method for Bromine Index of Aromatic Hydrocarbons by Electrometric Titration.

Keywords: ASTM D2710, bromine index, electrometric titration, petroleum hydrocarbons, unsaturated hydrocarbons, petroleum distillates, product quality control, reaction solvents, refinery testing.

For further details, always consult the full official standard as published by ASTM International to ensure compliance with all procedural and safety requirements.

Standards Content (Sample)

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: D2710 − 20
Designation: 299/92 (98)
Standard Test Method for
Bromine Index of Petroleum Hydrocarbons by Electrometric
Titration
This standard is issued under the fixed designation D2710; 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.
1. Scope* 2. Referenced Documents
1.1 This test method covers the determination of the amount 2.1 ASTM Standards:
of bromine-reactive material in petroleum hydrocarbons and is D1159 Test Method for Bromine Numbers of Petroleum
thus a measure of trace amounts of unsaturates in these Distillates and Commercial Aliphatic Olefins by Electro-
materials. It is applicable to materials having bromine indexes metric Titration
below 1000. D1492 Test Method for Bromine Index of Aromatic Hydro-
carbons by Coulometric Titration
1.2 This test method is applicable only to essentially olefin-
D5776 Test Method for Bromine Index of Aromatic Hydro-
free hydrocarbons or mixtures that are substantially free from
carbons by Electrometric Titration
material lighter than isobutane and have a distillation end point
under 288 °C (550 °F).
3. Terminology
NOTE 1—This procedure has been cooperatively tested on materials
with bromine indexes in the range from 100 to 1000. These materials
3.1 Definitions:
include petroleum distillates such as straight-run and hydrocracked
3.1.1 bromine index, n—the number of milligrams of bro-
naphtha, reformer feed, kerosine, and aviation turbine fuel.
mine that will react with 100 g of sample under the conditions
NOTE 2—Materials with bromine index greater than 1000 should be
of the test.
tested for bromine number using Test Method D1159/IP 130.
NOTE 3—Bromine index of industrial aromatic hydrocarbons should be
determined using Test Method D1492 or D5776. The subcommittee is
4. Summary of Test Method
currently examining ways to achieve more consistent end point values.
4.1 A known mass of the sample dissolved in a specified
1.3 The values stated in SI units are to be regarded as
solvent is titrated with standard bromide-bromate solution.The
standard. The values given in parentheses after SI units are
end point is indicated by a dead stop electrometric titration
provided for information only and are not considered standard.
apparatus when the presence of free bromine causes a sudden
1.4 This standard does not purport to address all of the
change in the electrical conductivity of the system.
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
5. Significance and Use
priate safety, health, and environmental practices and deter-
5.1 This test method provides a measure of trace amounts of
mine the applicability of regulatory limitations prior to use.
unsaturated hydrocarbons in petroleum distillates boiling up to
1.5 This international standard was developed in accor-
288 °C (550 °F).An estimate of the quantity of these materials
dance with internationally recognized principles on standard-
is useful in assessing the suitability of the lighter fractions for
ization established in the Decision on Principles for the
use as reaction solvents.
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
6. Apparatus
Barriers to Trade (TBT) Committee.
6.1 Electrometric End Point Titration Apparatus—Any ap-
paratus designed to perform titrations to pre-set end points (see
Note 4) may be used in conjunction with a high-resistance
This test method is under the jurisdiction of ASTM Committee D02 on
Petroleum Products, Liquid Fuels, and Lubricantsand is the direct responsibility of
Subcommittee D02.06 on Analysis of Liquid Fuels and Lubricants.
Current edition approved May 1, 2020. Published June 2020. Originally
approved in 1968. Last previous edition approved in 2018 as D2710 – 09 (2018). For referenced ASTM standards, visit the ASTM website, www.astm.org, or
DOI: 10.1520/D2710-20. contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
In the IP, this test method is under the jurisdiction of the Standardization Standards volume information, refer to the standard’s Document Summary page on
Committee. the ASTM website.
*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
D2710 − 20
polarizing current supply capable of maintaining approxi- removing the stopper. Shake vigorously, add 100 mL of water
mately 0.8 V across two platinum electrodes and with a in such a manner as to rinse the stopper, lip, and walls of the
sensitivity such that a voltage change of approximately 50 mV flask, and titrate promptly with the standard sodium thiosulfate
at these electrodes is sufficient to indicate the end point. Other (Na S O ) solution. Near the end of the titration, add 1 mL of
2 2 3
types of commercially available electric titrimeters, including starch indicator solution and titrate slowly to the disappearance
certain pH meters, have also been found to be suitable. of the blue color. Calculate the normality of the bromide-
NOTE 4—Pre-set end point indicated with polarized electrodes provides
bromate solution as follows:
a detection technique similar to the dead stop technique specified in
N 5 A N /A (1)
previous versions of this test method. 1 2 2 1
where:
6.2 Titration Vessel—A jacketed glass vessel of approxi-
mately 150 mL capacity of such a form that can be conve-
N = normality of the bromide-bromate solution,
niently maintained at 0 °C to 5 °C (32 °F to 41 °F). A pair of
A = millilitres of the bromide-bromate solution,
platinum electrodes spaced not more than 5 mm apart shall be N = normality of the Na S O solution, and
2 2 2 3
A = millilitres of the Na S O solution required for titration
mounted to extend well below the liquid level. Stirring shall be
2 2 2 3
by a mechanical or electromagnetic stirrer and shall be rapid, of the bromide-bromate solution.
but not so vigorous as to draw air bubbles down to the
7.3.2 Potassium Iodide Solution (150 g⁄L)—Dissolve 150 g
electrodes.
of KI in water and dilute to 1 L.
6.3 Burets, 10 mL and 50 mL capacity. 7.3.3 Sodium Thiosulfate, Standard Solution (0.05 N)—
Dissolve 12.5 g of sodium thiosulfate pentahydrate (Na S O ·
2 2 3
6.4 Iodine Number Flasks, glass-stoppered, 500 mL capac-
5H O) in water and add 0.01 g of sodium carbonate (Na CO )
2 2 3
ity.
to stabilize the solution. Dilute to 1 L and mix thoroughly by
shaking. Standardize by any accepted procedure that deter-
7. Reagents
mines the normality with an error not greater than 60.0002.
7.1 Purity of Reagents—Reagent grade chemicals shall be
Restandardizeatintervalsfrequentenoughtodetectchangesof
used in all tests. Unless otherwise indicated, it is intended that
0.0005 in normality.
all reagents shall conform to the specifications of theAmerican
7.3.4 Starch Indicator Solution—Mix 5 g of soluble starch
Chemical Society where such specifications are available.
with approximately 3 mL to 5 mL of water. If desired, add
Other grades may be used, providing it is first ascertained that
about 0.65 g salicylic acid as preservative. Add the slurry to
the reagent is of sufficiently high purity to permit its use
500 mL of boiling water and continue boiling for 5 min to
without lessening the accuracy of the determination.
10 min. Allow to cool and decant the supernatant liquid into
7.2 Purity of Water—Unless otherwise indicated, references
glass bottles and seal well. Starch solutions (some preserved
to water shall be understood to mean distilled water, or water
withsalicylicacid)arealsocommerciallyavailableandmaybe
of equivalent purity.
substituted.
7.3.5 Sulfuric Acid (1+5)—Carefully add 1 volume of
7.3 Preparation and Standardization:
concentrated sulfuric acid (H SO , sp gr 1.84) to 5 volumes of
7.3.1 Bromide-Bromate Standard Solution (0.05 N)—
2 4
water and thoroughly mix. (Warning—Poison. Corrosive.
Dissolve 5.1 g of potassium bromide (KBr) and 1.4 g potas-
Strong oxidizer. Contact with organic material may cause fire.
sium bromate (KBrO ) in water and dilute to 1 L. Standardize
May be fatal if swallowed.)
to four significant figures as follows: Place 50 mL of glacial
7.3.6 Titration Solvent—Prepare 1 L of titration solvent by
acetic acid (Warning—Poison. Combustible. May be fatal if
mixing the following volumes of materials: 714 mL of glacial
swallowed. Causes severe burns. Harmful if inhaled) and 1 mL
acetic acid, 134 mL of 1,1,1-trichloroethane or
of concentrated hydrochloric acid (HCl, sp gr 1.19)
dichloromethane, 134 mL of methanol, and 18
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D2710 − 09 (Reapproved 2018) D2710 − 20
Designation: 299/92 (98)
Standard Test Method for
Bromine Index of Petroleum Hydrocarbons by Electrometric
Titration
This standard is issued under the fixed designation D2710; 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.
1. Scope Scope*
1.1 This test method covers the determination of the amount of bromine-reactive material in petroleum hydrocarbons and is thus
a measure of trace amounts of unsaturates in these materials. It is applicable to materials having bromine indexes below 1000.
1.2 This test method is applicable only to essentially olefin-free hydrocarbons or mixtures that are substantially free from
material lighter than isobutane and have a distillation end point under 288 °C (550 °F).
NOTE 1—This procedure has been cooperatively tested on materials with bromine indexes in the range from 100 to 1000. These materials include
petroleum distillates such as straight-run and hydrocracked naphtha, reformer feed, kerosine, and aviation turbine fuel.
NOTE 2—Materials with bromine index greater than 1000 should be tested for bromine number using Test Method D1159/IP 130.
NOTE 3—Bromine index of industrial aromatic hydrocarbons should be determined using Test Method D1492 or D5776. The subcommittee is currently
examining ways to achieve more consistent end point values.
1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for
information only and are not considered standard.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of
regulatory limitations prior to use.
1.5 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.
This test method is under the jurisdiction of ASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricantsand is the direct responsibility of Subcommittee
D02.06 on Analysis of Liquid Fuels and Lubricants.
Current edition approved Dec. 1, 2018May 1, 2020. Published December 2018June 2020. Originally approved in 1968. Last previous edition approved in 20132018 as
D2710 – 09 (2013).(2018). DOI: 10.1520/D2710-09R18.10.1520/D2710-20.
In the IP, this test method is under the jurisdiction of the Standardization Committee.
*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
D2710 − 20
2. Referenced Documents
2.1 ASTM Standards:
D1159 Test Method for Bromine Numbers of Petroleum Distillates and Commercial Aliphatic Olefins by Electrometric Titration
D1492 Test Method for Bromine Index of Aromatic Hydrocarbons by Coulometric Titration
D5776 Test Method for Bromine Index of Aromatic Hydrocarbons by Electrometric Titration
3. Terminology
3.1 Definitions:
3.1.1 bromine index, n—the number of milligrams of bromine that will react with 100 g of sample under the conditions of the
test.
4. Summary of Test Method
4.1 A known mass of the sample dissolved in a specified solvent is titrated with standard bromide-bromate solution. The end
point is indicated by a dead stop electrometric titration apparatus when the presence of free bromine causes a sudden change in
the electrical conductivity of the system.
5. Significance and Use
5.1 This test method provides a measure of trace amounts of unsaturated hydrocarbons in petroleum distillates boiling up to
288 °C (550 °F). An estimate of the quantity of these materials is useful in assessing the suitability of the lighter fractions for use
as reaction solvents.
6. Apparatus
6.1 Electrometric End Point Titration Apparatus—Any apparatus designed to perform titrations to pre-set end points (see Note
4) may be used in conjunction with a high-resistance polarizing current supply capable of maintaining approximately 0.8 V across
two platinum electrodes and with a sensitivity such that a voltage change of approximately 50 mV at these electrodes is sufficient
to indicate the end point. Other types of commercially available electric titrimeters, including certain pH meters, have also been
found to be suitable.
NOTE 4—Pre-set end point indicated with polarized electrodes provides a detection technique similar to the dead stop technique specified in previous
versions of this test method.
6.2 Titration Vessel—A jacketed glass vessel of approximately 150 mL capacity of such a form that can be conveniently
maintained at 0 °C to 5 °C (32 °F to 41 °F). A pair of platinum electrodes spaced not more than 5 mm apart shall be mounted to
extend well below the liquid level. Stirring shall be by a mechanical or electromagnetic stirrer and shall be rapid, but not so
vigorous as to draw air bubbles down to the electrodes.
6.3 Burets, 10 mL and 50 mL capacity.
6.4 Iodine Number Flasks, glass-stoppered, 500 mL capacity.
7. Reagents
7.1 Purity of Reagents—Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that all
reagents shall conform to the specifications of the American Chemical Society where such specifications are available. Other
grades may be used, providing it is first ascertained that the reagent is of sufficiently high purity to permit its use without lessening
the accuracy of the determination.
7.2 Purity of Water—Unless otherwise indicated, references to water shall be understood to mean distilled water, or water of
equivalent purity.
7.3 Preparation and Standardization:
7.3.1 Bromide-Bromate Standard Solution (0.05 N)—Dissolve 5.1 g of potassium bromide (KBr) and 1.4 g potassium bromate
(KBrO ) in water and dilute to 1 L. Standardize to four significant figures as follows: Place 50 mL of glacial acetic acid
(Warning—Poison. Combustible. May be fatal if swallowed. Causes severe burns. Harmful if inhaled) and 1 mL of concentrated
hydrochloric acid (HCl, sp gr 1.19) (Warning—Poison. Corrosive. May be fatal if swallowed. Liquid and vapor cause severe
burns. Harmful if inhaled.) in a 500 mL iodine number flask. Chill the solution in an ice bath for approximately 10 min, and with
constant swirling of the flask, add from a 50 mL buret 40 mL to 45 mL of bromide-bromate solution, estimated to the nearest
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Reagent Chemicals, American Chemical Society Specifications,ACS Reagent Chemicals, Specifications and Procedures for Reagents and Standard-Grade Reference
Materials, American Chemical Society, Washington, DC. For Suggestionssuggestions on the testing of reagents not listed by the American Chemical Society, see
AnnualAnalar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and National Formulary, U.S. Pharmacopeial
Convention, Inc. (USPC), Rockville, MD.
D2710 − 20
0.01 mL, at a rate such that the addition takes between 90 s and 120 s. Stopper the flask immediately, shake the contents, place
it again in the ice bath, and add 5 mL of potassium iodide (KI) solution in the lip of the flask. After 5 min, remove the flask from
the ice bath and allow the KI solution to flow into the flask by slowly removing the stopper. Shake vigorously, add 100 mL of water
in such a manner as to rinse the stopper, lip, and walls of the flask, and titrate promptly with the standard sodium thiosulfate
(Na S O ) solution. Near the end of the titration, add 1 mL of starch indicator solution and titrate slowly to the disappearance of
2 2 3
the blue color. Calculate the normality of the bromide-bromate solution as follows:
N 5 A N /A (1)
1 2 2 1
where:
N = normality of the bromide-bromate solution,
A = millilitres of the bromide-bromate solution,
N = normality of the Na S O solution, and
2 2 2 3
A = millilitres of the Na S O solution required for titration of the bromide-bromate solution.
2 2 2 3
7.3.2 Potassium Iodide Solution (150 g ⁄L)—Dissolve 150 g of KI in water and dilute to 1 L.
7.3.3 Sodium Thiosulfate, Standard Solution (0.05N)—Dissolve 12.5 g of sodium thiosulfate pe
...