Methyl orange - wikipedia Methyl orange Methyl orange Names Preferred IUPAC name Sodium 4 - ( ( 4 - ( dimethylamino ) phenyl ) diazenyl ) benzene - 1 - sulfonate Other names Sodium 4 - ( ( 4 - dimethylamino ) phenylazo ) benzenesulfonate Identifiers CAS Number 547 - 58 - 0 3D model ( JSmol ) Interactive image ChemSpider 16736152 ECHA InfoCard 100.008. 115 InChI InChI = 1S / C14H15N3O3S.Na/c1-17 ( 2 ) 13 - 7 - 3 - 11 ( 4 - 8 - 13 ) 15 - 16 - 12 - 5 - 9 - 14 ( 10 - 6 - 12 ) 21 ( 18, 19 ) 20 ; / h3 - 10H, 1 - 2H3, ( H, 18, 19, 20 ) ; / q ; + 1 / p - 1 Key : STZCRXQWRGQSJD - UHFFFAOYSA - M InChI = 1 / C14H15N3O3S.Na/c1-17 ( 2 ) 13 - 7 - 3 - 11 ( 4 - 8 - 13 ) 15 - 16 - 12 - 5 - 9 - 14 ( 10 - 6 - 12 ) 21 ( 18, 19 ) 20 ; / h3 - 10H, 1 - 2H3, ( H, 18, 19, 20 ) ; / q ; + 1 / p - 1 Key : STZCRXQWRGQSJD - REWHXWOFAG SMILES ( Na+ ). CN ( C ) c2ccc ( / N = N / c1ccc ( cc1 ) S ( ( O - ) ) ( = O ) = O ) cc2 Properties Chemical formula C H N Na O S Molar mass 327.33 g mol Density 1.28 g / cm, solid Melting point > 300 ° C ( 572 ° F ; 573 K ) not precisely defined Boiling point decomposes Solubility in water 0.5 g / 100 mL ( 20 ° C ) Solubility insoluble in diethyl ether Hazards Main hazards Toxic ( T ) GHS pictograms GHS signal word Danger GHS hazard statements H301 GHS precautionary statements P308, P310 NFPA 704 0 0 Lethal dose or concentration ( LD, LC ) : LD ( median dose ) 60 mg / kg ( rat, oral ) Except where otherwise noted, data are given for materials in their standard state ( at 25 ° C ( 77 ° F ), 100 kPa ). Y verify ( what is ? ) Infobox references Methyl orange is a pH indicator frequently used in titrations because of its clear and distinct colour change. Because it changes colour at the pH of a midstrength acid, it is usually used in titrations for acids. Unlike a universal indicator, methyl orange does not have a full spectrum of colour change, but has a sharper end point. Methyl orange shows red colour in acidic medium and yellow colour in basic medium. Contents 1 Indicator colours 2 Other indicators 3 Safety 4 See also 5 References 6 External links Indicator colours Methyl orange solutions In a solution becoming less acidic, methyl orange moves from red to orange and finally to yellow with the reverse occurring for a solution increasing in acidity. The entire color change occurs in acidic conditions. Methyl orange ( pH indicator ) below pH 3.1 above pH 4.4 3.1 ⇌ 4.4 In an acid, it is reddish and in alkali, it is yellow. Methyl orange has a pK of 3.47 in water at 25 ° C ( 77 ° F ). Other indicators Main article : pH indicator Methyl orange in xylene cyanol solution ( pH indicator ) below pH 3.2 above pH 4.2 3.2 ⇌ 4.2 Modified ( or screened ) methyl orange, an indicator consisting of a solution of methyl orange and xylene cyanol, changes from grey - violet to green as the solution becomes more basic. Safety Methyl orange has mutagenic properties. Direct contact should be avoided. See also pH indicator Methyl red Litmus Phenolphthalein Bromothymol blue Universal indicator References ^ Jump up to : MSDS from ScienceLab.com, Inc. Retrieved 2011 - 09 - 24 Jump up ^ Sandberg, Richard G. ; Henderson, Gary H. ; White, Robert D. ; Eyring, Edward M. ( 1972 ). `` Kinetics of acid dissociation - ion recombination of aqueous methyl orange ''. The Journal of Physical Chemistry. 76 ( 26 ) : 4023 -- 4025. doi : 10.1021 / j100670a024. External links Wikimedia Commons has media related to Methyl orange. Informative page on different titration indicators, including Methyl Orange Retrieved from `` https://en.wikipedia.org/w/index.php?title=Methyl_orange&oldid=808727555 '' Categories : PH indicators Azo dyes Benzenesulfonates Anilines Organic sodium salts Hidden categories : Chemicals without a PubChem CID Articles without EBI source Articles without KEGG source Articles without UNII source ECHA InfoCard ID from Wikidata Chembox having GHS data Articles containing unverified chemical infoboxes Talk Contents About Wikipedia تۆرکجه Bosanski Čeština Dansk Deutsch Eesti Ελληνικά Español Esperanto فارسی Français Gaeilge 한국어 Hrvatski Bahasa Indonesia Italiano Қазақша Latviešu Nederlands 日本 語 Polski Português Română Русский Slovenčina Slovenščina Српски / srpski Srpskohrvatski / српскохрватски Suomi தமிழ் తెలుగు ไทย Türkçe Українська 中文 Edit links This page was last edited on 4 November 2017, at 19 : 33. About Wikipedia

Question: what color does methyl orange turn in an acid
Answer: red