GB/T 639-2008 in English

《GB/T 639-2008化学试剂 无水碳酸钠》由TC63（全国化学标准化技术委员会）归口，TC63SC3（全国化学标准化技术委员会化学试剂分会）执行，主管部门为中国石油和化学工业联合会。
本标准规定了化学试剂中无水碳酸钠的性状、规格、试验、检验规则和包装及标志。本标准适用于化学试剂中无水碳酸钠的检验。本标准适用于化学试剂中无水碳酸钠的检验。

Molecular formula: Na2CO3

Relative molecular mass: 105.99 (according to the international relative atomic mass in 2005).

1 Scope

This standard specifies the characteristics, specifications, tests, inspection rules, packaging and marking of sodium carbonate anhydrous in chemical reagents.

This standard is applicable to the inspection of sodium carbonate anhydrous in chemical reagents.

2 Normative references

The following documents contain provisions which, through reference in this text, constitute provisions of this standard. For dated references, subsequent amendments (excluding corrections), or revisions, of any of these publications do not apply to this standard. However, parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. For undated references, the latest edition of the normative document referred to applies.

GB/T 601 Chemical reagent - Preparations of reference titration solutions
GB/T 602 Chemical reagent - Preparations of standard solutions for impurity (GB/T 602-2002, ISO 6353-1: 1982, NEQ)
GB/T 603 Chemical reagent - Preparations of reagent solutions for use in test methods (GB/T 603-2002, ISO 6353-1: 1982, NEQ)
GB/T 609 Chemical reagent - General method for the determination of total nitrogen (GB/T 609-2006, ISO 6353-1: 1982)
GB/T 6682 Water for analytical laboratory use - Specification and test methods (GB/T 6682-2008, ISO 3696: 1987, MOD)
GB/T 9723-2007 Chemical reagent - General rule for flame atomic absorption spectrometric analysis
GB/T 9728 Chemical reagent - General method for the determination of sulphate (GB/T 9728-2007, ISO 6353-1: 1982, NEQ)
GB/T 9729 Chemical reagent - General method for the determination of chloride (GB/T 9729-2007, ISO 6353-1: 1982, NEQ)
GB/T 9734-2008 Chemical reagent - General method for the determination of aluminum (ISO 6353-1: 1982, NEQ)
GB/T 9738 Chemical reagent - General method for the determination of water insoluble matter (GB/T 9738-2008, ISO 6353-1: 1982, NEQ)
GB/T 9739 Chemical reagent - General method for the determination of iron (GB/T 9739-2006, ISO 6353-1: 1982, NEQ)
GB 15346 Chemical reagent - Packaging and marking
HG/T 3484 Chemical reagent - standard of clear liquor, made from glass dust, and standard of transparence
HG/T 3921 Chemical reagent - Regulations for sampling and acceptance

3 Characteristics

The reagent is a kind of white powder, which gradually absorbs water into monohydrate when exposed to air, and is soluble in water while insoluble in ethanol.

4 Specifications

See Table 1 for the specifications of sodium carbonate anhydrous.

Foreword i
1 Scope
2 Normative references
3 Characteristics
4 Specifications
5 Tests
6 Inspection rules
7 Packaging and marking