ASTM_D_852_-_13.pdf

Designation:D85213Standard Test Method forSolidification Point of Benzene1This standard is issued under the fixed designation D852;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope*1.1 This test method covers the determination of the solidi-fication point of benzene.1.2 In determining the conformance of the test results usingthis method to applicable specifications,results shall berounded off in accordance with the rounding-off method ofPractice E29.1.3 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.4 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.For specific hazardstatements,see Section 7.2.Referenced Documents2.1 ASTM Standards:2D1015 Test Method for Freezing Points of High-PurityHydrocarbonsD1016 Test Method for Purity of Hydrocarbons from Freez-ing PointsD1193 Specification for Reagent WaterD3437 Practice for Sampling and Handling Liquid CyclicProductsD6809 Guide for Quality Control and Quality AssuranceProcedures for Aromatic Hydrocarbons and Related Ma-terialsE1 Specification for ASTM Liquid-in-Glass ThermometersE29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method2.2 Other Document:OSHA Regulations,29 CFR paragraphs 1910.1000 and1910.120033.Terminology3.1 Definitions:3.1.1 solidification point,nan empirical constant definedas the temperature at which the liquid phase of a substance isin approximate equilibrium with a relatively small portion ofthe solid phase.3.1.1.1 DiscussionSolidification point is distinguishedfrom freezing point which is described in Test Method D1015.An interpretation of mol percent purity in terms of freezingpoint is given in Test Method D1016.4.Summary of Test Method4.1 Solidification point is measured by noting the maximumtemperature reached during a controlled cooling cycle after theappearance of a solid phase.5.Significance and Use5.1 This test method may be used as a criteria for determin-ing the purity of benzene.The closer the solidification pointreaches that of pure benzene,the purer the sample.6.Apparatus6.1 Benzene Container(Air Jacketed):6.1.1 Inner Container,a test tube 15 mm in outside diameterand 125 mm in length.6.1.2 Air Jacket,a standard test tube 25 mm in outsidediameter and 150 mm in length.6.1.3 InsulationDry absorbent cotton or glass wool.6.2 Benzene Container(thick walled),a glass test tube 18mm in outside diameter,14 mm in inside diameter and 150 mmin length.The thick walled tube is only compatible with thethermistor.1This test method is under the jurisdiction of ASTM Committee D16 onAromatic Hydrocarbons and Related Chemicals and is the direct responsibility ofSubcommittee D16.01 on Benzene,Toluene,Xylenes,Cyclohexane and TheirDerivatives.Current edition approved July 1,2013.Published August 2013.Originallyapproved in 1945.Last previous edition approved in 2008 as D852 08.DOI:10.1520/D0852-13.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3Available from U.S.Government Printing Office Superintendent of Documents,732 N.Capitol St.,NW,Mail Stop:SDE,Washington,DC 20401,http:/www.access.gpo.gov.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 6.3 Ice Bath,a 1-L beaker,or similar suitable container,having an effective depth of at least 127 mm and filled withchipped or shaved ice.6.4 Stirrer,consisting of a 1-mm wire(copper or stainlesssteel)or a 2-mm glass rod with one end bent into a circularform at right angles to the shaft so that it will move freely inthe annular space between the thermometer stem and the wallof the smaller test tube.6.5 Temperature Measurement Device,either device de-scribed below has been found satisfactory.6.5.1 Thermometer,anASTM Benzene Freezing Point Ther-mometer having a range from 4.0 to 6.0C and conforming tothe requirements for Thermometer 112C as prescribed inSpecification E1.6.5.2 Thermistor,in stainless steel housing with resistancegreater than 2K ohms at 25C.Calibration accuracy 0.01C.Drift in resistance equivalent to less than 60.01C/year.Thermistor shall be calibrated to cover the range it is used.46.6 Stirring Apparatus(Optional),