GB/T 4348.1-2013 English PDF (GBT4348.1-2013)

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GB/T 4348.1-2013: Sodium hydroxide for industrial use -- Determination of sodium hydroxide and sodium carbonate content
GB/T 4348.1-2013
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 71.060.40
G 11
Replace GB/T 4348.1-2000
Sodium hydroxide for industrial use - Determination of
sodium hydroxide and sodium carbonate content
ISSUED ON: SEPTEMBER 6, 2013
IMPLEMENTED ON: JANUARY 31, 2014
Issued by: General Administration of Quality Supervision, Inspection and
Quarantine of PRC;
Standardization Administration of PRC.
Table of Contents
Foreword ... 3
1 Scope ... 5
2 Normative references ... 5
3 Principles ... 5
4 Reagents ... 6
5 Instruments ... 6
6 Analysis steps ... 6
7 Calculation of results ... 7
8 Test report ... 8
Sodium hydroxide for industrial use - Determination of
sodium hydroxide and sodium carbonate content
1 Scope
This standard specifies the determination method of sodium hydroxide and sodium
carbonate content in sodium hydroxide for industrial use.
This standard applies to the determination of sodium hydroxide and sodium carbonate
content in sodium hydroxide for industrial use.
2 Normative references
The following documents are essential to the application of this document. For the dated
documents, only the versions with the dates indicated are applicable to this document;
for the undated documents, only the latest version (including all the amendments) is
applicable to this standard.
GB/T 601 Chemical reagent - Preparations of reference titration solutions
GB/T 603 Chemical reagent - Preparations of reagent solutions for use in test
methods
GB/T 6682 Water for analytical laboratory use - Specification and test methods
(GB/T 6682-2008, ISO 3696:1987, MOD)
3 Principles
3.1 Determination principle of sodium hydroxide content
The barium chloride is added to the sample solution, so that the sodium carbonate is
converted into barium carbonate precipitate; then, phenolphthalein is used as the
indicator solution, and hydrochloric acid standard titration solution is used to titrate to
the end point. The reaction is as follows:
3.2 Determination principle of sodium carbonate content
The bromocresol green-methyl red mixed indicator solution is used as the indicator
solution for the sample solution, and the hydrochloric acid standard titration solution is
used to titrate to the end point, so that the sum of sodium hydroxide and sodium
carbonate is measured; then, the content of sodium hydroxide is subtracted, and the
sodium carbonate content can be measured.
4 Reagents
4.1 General provisions
Unless otherwise specified, the reagents and water used in this method refer to
analytically pure reagents and Grade III water (free of carbon dioxide) specified in
GB/T 6682 or water of equivalent purity.
Unless otherwise specified, the standard titration solutions, preparations, and products
required in the test shall be prepared according to the provisions of GB/T 601 and GB/T
603.
4.2 Barium chloride solution: 100 g/L;
Before use, phenolphthalein (4.4) is used as the indicator solution, and the solution is
adjusted to reddish color with standard sodium hydroxide solution.
4.3 Hydrochloric acid standard titration solution: c(HCl)=1 mol/L;
4.4 Phenolphthalein indicator solution: 10 g/L;
4.5 Bromocresol green-methyl red indicator solution.
5 Instruments
General laboratory instruments and the following instruments.
5.1 Single-scale pipette: 50 mL, Type A;
5.2 Burette: 50 mL, with a division value of 0.1 mL, Type A;
5.3 Magnetic stirrer.
6 Analysis steps
6.1 Preparation of sample solution
Use a weighing bottle to quickly weigh 30 g±1 g of solid sodium hydroxide or 50 g±1