2480 NTERNATIONAL STANDARD (TSO) INTERNATIONAL ORGANIZATION FOR STANDARDIZATION MEKIYHAPOAHAS OPTAHI3ALIWS HIO CTAHIAPTH3ALIW.ORGANISATION INTERNATIONALE DE NORMALISATION Sodium chloride for industrial use - Determination of sulphate content -- Barium sulphate gravimetric method First edition - 1972-12-15 ISO 2480-1972 (E) Ref. No. ISO 2480-1972 (E) UDC 661.833.321 :546.226 : 543.21 Descriptors : sodium chioride, chemical analysis, gravimetric analysis, determination of content, sulphates. Price based on 4 pages Copyright International Organization for Standardization Not for Resale FOREWORD ISo (the International Organization for Standardization) is a worldwide federation of national standards institutes (ISO Member Bodies). The work of developing International Standards is carried out through ISO Technical Committees. Every Member Body interested in a subject for which a Technical Committee has been set up has the right to be represented on that Committee. International organizations, governmental and non-governmental, in liaison with IsO, also take part in the work. Draft International Standards adopted by the Technical Committees are circulated to the Member Bodies for approval before their acceptance as International Standards by the ISo Council. International Standard IsO 2480 was drawn up by Technical Committee ISO/TC 47,Chemistry. It was approved in January 1972 by the Member Bodies of the following countries : India Portugal Austria Ireland Belgium Romania South Africa, Rep. of Chile Italy Korea, Dem.P.Rep. of Czechoslovakia Spain Egypt, Arab Rep. of Morocco Switzerland Netherlands France Thailand Germany New Zealand United Kingdom U.S.S.R. Hungary Poland The Member Body of the following country expressed disapproval of the document on technical grounds : U.S.A. @ International Organization for Standardization, 1972 : Printed in Switzerland Copyright International Organization for Standardization Not for Resale INTERNATIONAL STANDARD ISO 2480-1972 (E) Sodium chloride for industrial use -- Determination of sulphate content -- Barium sulphate gravimetric method 1 SCOPE 5.2 Sulphuric acid, p 1,84 g/ml (approximately 96% (m/m) solution or approximately 36 N). This International Standard specifies a gravimetric method for the determination of sulphate content of sodium 5.3 Barium chloride, approximateiy N solution. chloride for industrial use. Dissolve 122 g of barium chloride dihydrate in water in a 1 000 ml one-mark volumetric flask, ditute to the mark and 2 FIELD OF APPLICATION mix. 2.1 General case 5.4 Silver nitrate, 5 g/l nitric solution The method is applicable to the determination of sulphate Dissolve 0,5 g of silver nitrate in a little water, add 10 ml of soluble in water, in sodium chloride for industrial use. nitric acid solution, p 1;40 g/ml approximately, and dilute to 100 ml. 2.2 Special case 5.5 Nitric acid p 1,40 g/ml (approximately 68 % (m/m) Determination of sulphate in a principal solution prepared solution, or approximately 14 N). in an acid medium. NOTE - allrelated determinations shall be carried out in the same medium, except the determination of chlorides which shall aiways be carried out in an 6 APPARATUS aqueous solution. Ordinary laboratory apparatus and 3 REFERENCE 6.1 Electric furnace, capable of being controlled at ISO 2479, Sodium chloride for industrial use 800 ± 25 °c. Determination of matter insoluble in water or acid and for other preparation of principal 6.2 Desiccator, containing pumice moistened with determinations. sulphuric acid, silica gel, or phosphorus pentoxide. 4 PRINCIPLE 6.3 Platinum or porcelain crucibles, approximately 30 mm diameter at the top, and approximately 30 mm deep. Dissolution of a test portion and separation of the insoluble residue. 7 PROCEDURE Precipitation of the sulphate jons as barium sulphate in a boiling acid medium. Filtration, washing and ignition of the precipitate. Weighing of the barium sulphate. 7.1 Test portion Take 100,0 ml of the principal soluti