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1、INTERNATIONAL STANDARD INTERNATIONAL ORGANIZATION FOR STANDARDiZiiT,3N.,E.i:IYH4POI4I OI I-AH113411M11 n0 CTAH;IPTMAIIMM.ORGANISATION INTERNATIONALE DE NORMAUSATION Sodium carbonate for industrial use - Determination of total soluble alkalinity - Titrimetric method Carbonate de sodium B usage indust
2、riel - De termination de I alcalinite totale soluble - Mkthode titrimktrique First edition - 1976-02-01 z UDC 661.833.622 : 543.241.2 Ref. No. IS0 740-1976 (E) z 03 - Descriptors : sodium carbonate, chemical analysis, determination of content, alkalinity, solubility. ? s Price based on 2 pages Copyr
3、ight International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/25/2007 22:11:47 MDTNo reproduction or networking permitted without license from IHS -,-,- FOREWORD IS0 (the International Organization for Sta
4、ndardization) is a worldwide federation of national standards institutes (IS0 Member Bodies). The work of developing International Standards is carried out through IS0 Technical Committees. Every Member Body interested in a subject for which a Technical Committee has been set up has the right to be
5、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
6、Standards by the IS0 Council. Prior to 1972, the results of the work of the Technical Committees were published as 150 Recommendations; these documents are now in the process cf being transformed into International Standards. As part of this process, Technical Committee ISO/TC 47 has reviewed IS0 Re
7、commendation R 740 and found it technically suitable for transformation. International Standard IS0 740 therefore replaces IS0 Recommendation R 740-1968 to which it is technically identical. IS0 Recommendation R 740 was approved by the Member Bodies of the following countries : Austria Belgium Brazi
8、l Chile Czechoslovakia Egypt, Arab Rep. of France Germany Hungary India Israel Italy Japan Korea, Rep. of Netherlands New Zealand Poland Portugal Romania South Africa, Rep. of Spain Switzerland Turkey United Kingdom U.S.A. U.S.S.R. Yugoslavia No Member Body expressed disapproval of the Recommendatio
9、n. No Member Body disapproved the transformation of ISO/R 740 into an International Standard. 0 International Organization for Standardization, 1976 l Printed in Switzerland Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standa
10、rds 1/9972545001 Not for Resale, 04/25/2007 22:11:47 MDTNo reproduction or networking permitted without license from IHS -,-,- INTERNATIONAL STANDARD IS0 740-1976 (El Sodium carbonate for industrial use - Determination of total soluble alkalinity - Titrimetric method 1 SCOPE AND FIELD OF APPLICATION
11、 This International Standard specifies a titrimetric method for the determination of the total soluble alkalinity of sodium carbonate for industrial use. 2 REFERENCES IS0 739, Sodium carbonate for industrial use - Preparation and storage of test samples. IS0 745, Sodium carbonate for industrial use
12、- Deter- mination of loss of mass and of non-volatile matter at 250 C. 3 fRiNCIP LE Solution of a test portion, filtration of the solution and titration of the total soluble alkalinity with a standard volumetric solution of hydrochloric acid, using methyl orange as indicator. 4 REAGENTS During the a
13、nalysis, use only reagents of recognized analytical reagent grade and only distilled water or water of equivalent purity. 4.1 Hydrochloric acid, 1 N standard volumetric solution. 4.2 Methyl orange, 0,5 g/l solution. NOTE - The methyl orange may be replaced by any other indicator giving the same end-
14、point. 5 APPARATUS Ordinary laboratory apparatus. 6 PROCEDURE 6.1 Test portion Weigh, to the nearest 0,Ol g, a mass of the test sample (see IS0 739) of 50 f 0,l g, 59 f 0,l g, 110 + 0,l g or 135 + 0,l g, depending on whether the product is anhydrous or mono-, hepta- or decahydrate. 6.2 Preparation o
15、f test solution Dissolve the test portion (6.1) by pouring it in small quantities at a time, while stirring, into a beaker of suitable capacity (for example 600 ml) containing 200 ml of water at about 50 “C. Filter the decanted solution through a medium-speed filter, collecting the filtrate in a 500
16、 ml one-mark volumetric flask. Wash the insoluble matter onto the filter with water at about 50 “C. Complete the washing, collecting all the washings in the volumetric flask. Allow to cool, dilute to the mark and mix. 6.3 Titration Transfer 25,0 ml of the test solution (6.2) to a 500 ml conical flas
17、k. Add approximately 75 ml of water, 5 drops of the methyl orange solution (4.2) and titrate with the standard volumetric hydrochloric acid solution (4.1) until the indicator turns from yellow to orange-pink. NOTE - If required, this determination may also be carried out by means of back-titration,
18、using 1 N standard volumetric hydro- chloric acid solution and 1 N or 0.1 N standard volumetric sodium hydroxide solution. If this method is adopted, it shall be taken into account in the calculation of results. 7 EXPRESSION OF RESULTS The total soluble alkalinity, expressed as a percentage by mass
19、of sodium carbonate (Na2C0a), is given by the formula : 500 100 vx25 x-x0,053 0= 10Sv m m where V is the volume, in millilitres, of the standard volumetric hydrochloric acid solution (4.1) used for the titration; m is the mass, in grams, of the test portion (6.1); 0,053 0 is the mass, in grams, of s
20、odium carbonate equivalent to 1 ml of exactly 1 N standard volumetric hydrochloric acid solution. NOTES 1 If the concentration of the standard volumetric solution used is not exactly as specified in the list of reagents, an appropriate correction should be made. 2 If it is desired to express the res
21、ult on the basis of non-volatile matter at 250 “C (see IS0 7451, multiply the result obtained on the product as received by the ratio 100 100 - loss of mass at 250 “C in % (m/m) Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical St
22、andards 1/9972545001 Not for Resale, 04/25/2007 22:11:47 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 740-1976 (El 8 TEST REPORT The test report shall include the following particulars : c) any unusual features noted during the determination. a) the reference of the
23、method used; d) any operation not included in this International Standard or in the international Standards to which b) the results and the method of expression used; reference is made, or regarded as optional. ANNEX IS0 PUBLICATIONS RELATING TO SODIUM CARBONATE FOR INDUSTRIAL USE IS0 739 - Preparat
24、ion and storage of test samples. IS0 740 - Determination of total soluble alkalinity - Titrimetric method. IS0 741 - Determination of sodium hydrogen carbonate content - Titrimetric method. IS0 742 - Determination of chloride content - Mercurimetric method. IS0 743 - Determination of sulphate conten
25、t - Barium sulphate gravimetric method. IS0 744 - Determination of iron content - 1 ,lO-Phenanthroline photometric method. IS0 745 - Determination of loss of mass and of non-volatile matter at 250 “C. IS0 746 - Determination of matter insoluble in water at 50 “C. 2 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/25/2007 22:11:47 MDTNo reproduction or networking permitted without license from IHS -,-,-
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