Phenolphthalein - wikipedia Phenolphthalein `` Phph '' redirects here. For Ph - Ph, see biphenyl. Phenolphthalein Names Preferred IUPAC name 3, 3 - Bis ( 4 - hydroxyphenyl ) - 2 - benzofuran - 1 ( 3H ) - one Other names 3, 3 - Bis ( 4 - hydroxyphenyl ) isobenzofuran - 1 ( 3H ) - one Identifiers CAS Number 77 - 09 - 8 3D model ( JSmol ) Interactive image ChEMBL ChEMBL63857 ChemSpider 4600 DrugBank DB04824 ECHA InfoCard 100.000. 914 KEGG D05456 PubChem CID 4764 UNII 6QK969R2IF InChI InChI = 1S / C20H14O4 / c21 - 15 - 9 - 5 - 13 ( 6 - 10 - 15 ) 20 ( 14 - 7 - 11 - 16 ( 22 ) 12 - 8 - 14 ) 18 - 4 - 2 - 1 - 3 - 17 ( 18 ) 19 ( 23 ) 24 - 20 / h1 - 12, 21 - 22H Key : KJFMBFZCATUALV - UHFFFAOYSA - N InChI = 1 / C20H14O4 / c21 - 15 - 9 - 5 - 13 ( 6 - 10 - 15 ) 20 ( 14 - 7 - 11 - 16 ( 22 ) 12 - 8 - 14 ) 18 - 4 - 2 - 1 - 3 - 17 ( 18 ) 19 ( 23 ) 24 - 20 / h1 - 12, 21 - 22H Key : KJFMBFZCATUALV - UHFFFAOYAH SMILES O = C1OC ( c2ccccc12 ) ( c3ccc ( O ) cc3 ) c4ccc ( O ) cc4 Properties Chemical formula C H O Molar mass 318.33 g mol Appearance White powder Density 1.277 g / cm ( 32 ° C ( 90 ° F ) ) Melting point 258 -- 263 ° C ( 496 -- 505 ° F ; 531 -- 536 K ) Solubility in water 400 mg / L in water Solubility in other solvents Insoluble in benzene or hexane, very soluble in ethanol and ether, slightly soluble in DMSO UV - vis ( λ ) 552 nm ( 1st ) 374 nm ( 2nd ) Pharmacology ATC code A06AB04 ( WHO ) Hazards GHS pictograms GHS signal word Danger GHS hazard statements H341, H350, H361 GHS precautionary statements P201, P281, P308 + 313 NFPA 704 0 Except where otherwise noted, data are given for materials in their standard state ( at 25 ° C ( 77 ° F ), 100 kPa ). verify ( what is ? ) Infobox references Phenolphthalein is a chemical compound with the formula C H O and is often written as `` HIn '' or `` phph '' in shorthand notation. Phenolphthalein is often used as an indicator in acid -- base titrations. For this application, it turns colorless in acidic solutions and pink in basic solutions. It belongs to class of dyes known as Pthalein dyes. Phenolphthalein is slightly soluble in water and usually is dissolved in alcohols for use in experiments. It is a weak acid, which can lose H ions in solution. The phenolphthalein molecule is colorless, and the phenolphthalein ion is pink. When a base is added to the phenolphthalein, the molecule ⇌ ions equilibrium shifts to the right, leading to more ionization as H ions are removed. This is predicted by Le Chatelier 's principle. Contents 1 Uses 1.1 Indicator 1.2 Medical uses 2 Synthesis 3 See also 4 References 5 External links Uses Indicator Phenolphthalein 's common use is as an indicator in acid - base titrations. It also serves as a component of universal indicator, together with methyl red, bromothymol blue, and thymol blue. Phenolphthalein adopts four different states in aqueous solution : Under very strongly acidic conditions, it exists in protonated form ( HIn ), providing an orange coloration. Between strongly acidic and slightly basic conditions, the lactone form ( HIn ) is colorless. The doubly deprotonated ( In ) phenolate form ( the anion form of phenol ) gives the familiar pink color. In strongly basic solutions, phenolphthalein 's pink color undergoes a rather slow fading reaction and becomes completely colorless above 13.0 pH. The rather slow fading reaction that produces the colorless In ( OH ) ion is sometimes used in classes for the study of reaction kinetics. Species H In H In In In ( OH ) Structure Model pH < 0 0 − 8.2 8.2 − 12.0 > 13.0 Conditions strongly acidic acidic or near - neutral basic strongly basic Color orange colorless pink to fuchsia colorless Image An animation of the pH dependent reaction mechanism : H In → H In → In → In ( OH ) Phenolphthalein 's pH sensitivity is exploited in other applications : Concrete has naturally high pH due to the calcium hydroxide formed when Portland cement reacts with water. As the concrete reacts with carbon dioxide in the atmosphere, pH decreases to 8.5 - 9. When a 1 % phenolphthalein solution is applied to normal concrete, it turns bright pink. However, if it remains colorless, it shows that the concrete has undergone carbonation. In a similar application, spackling used to repair holes in drywall contains phenolphthalein. When applied, the basic spackling material retains a pink coloration ; when the spackling has cured by reaction with atmospheric carbon dioxide, the pink color fades. Phenolphthalein is used in toys, for example as a component of disappearing inks, or disappearing dye on the Hollywood Hair Barbie hair. In the ink, it is mixed with sodium hydroxide, which reacts with carbon dioxide in the air. This reaction leads to the pH falling below the color change threshold as hydrogen ions are released by the reaction : OH + CO → CO + H To develop the hair and `` magic '' graphical patterns, the ink is sprayed with a solution of hydroxide, which leads to the appearance of the hidden graphics by the same mechanism described above for color change in alkaline solution. The pattern will eventually disappear again because of the reaction with carbon dioxide. Thymolphthalein is used for the same purpose and in the same way, when a blue color is desired. Medical uses See also : Phenol red Phenolphthalein has been used for over a century as a laxative, but is now being removed from over-the - counter laxatives because of concerns over carcinogenicity. Thymolphthalein is a related laxative made from thymol. Despite concerns regarding its carcinogenicity, the use of phenolphthalein as a laxative is unlikely to cause ovarian cancer. Phenolphthalein has been found to inhibit human cellular calcium influx via store - operated calcium entry ( SOCE, see Calcium release activated channel § Structure ). This is effected by its inhibiting thrombin and thapsigargin, two activators of SOCE that increase intracellular free calcium. Phenolphthalein has been added to the European Chemicals Agency 's candidate list for Substances of Very High Concern ( SVHC ). A reduced form of phenolphthalein, phenolphthalin, which is colorless, is used in a test to identify substances thought to contain blood, commonly known as the Kastle - Meyer test. A dry sample is collected with a swab or filter paper. A few drops of alcohol, then a few drops of phenolphthalin, and finally a few drops of hydrogen peroxide are dripped onto the sample. If the sample contains hemoglobin, it will turn pink immediately upon addition of the peroxide, because of the generation of phenolphthalein. A positive test indicates the sample contains hemoglobin and, therefore, is likely blood. A false positive can result from the presence of substances with catalytic activity similar to heme. This test is not destructive to the sample ; it can be kept and used in further tests. This test has the same reaction with blood from any animal, so further testing would be required to determine whether it originates from a human. Synthesis Phenolphthalein can be synthesized by condensation of phthalic anhydride with two equivalents of phenol under acidic conditions ( hence the name ). It was discovered in 1871 by Adolf von Baeyer. Synthesis of phenolphthalein : The reaction can also be catalyzed by a mixture of zinc chloride and thionyl chloride. See also Bromothymol blue Litmus Methyl orange pH indicator Universal indicator References ^ Jump up to : `` Phenolphthalein ''. Retrieved 7 October 2014. Jump up ^ `` Universal Indicator ''. ISCID Encyclopedia of Science and Philosophy. Archived from the original on September 25, 2006. Jump up ^ US 6531528, Ronald D. Kurp, `` Ready to use spackle / repair product containing dryness indicator '', assigned to Dap Products Inc. Jump up ^ Toystore Jump up ^ Spiller, H.A. ; Winter, M.L. ; Weber, J.A. ; Krenzelok, E.P. ; Anderson, D.L. ; Ryan, M.L. ( May 2003 ). `` Skin Breakdown and Blisters from Senna - Containing Laxatives in Young Children ''. The Annals of Pharmacotherapy. 37 ( 5 ) : 636 -- 639. doi : 10.1345 / aph. 1C439. PMID 12708936. Jump up ^ Dunnick, J.K. ; Hailey, J.R. ( 1996 ). `` Phenolphthalein Exposure Causes Multiple Carcinogenic Effects in Experimental Model Systems '' ( pdf ). Cancer Research. 56 ( 21 ) : 4922 -- 4926. PMID 8895745. Jump up ^ Tice, R.R. ; Furedi - Machacek, M. ; Satterfield, D. ; Udumudi, A. ; Vasquez, M. ; Dunnick, J.K. ( 1998 ). `` Measurement of Micronucleated Erythrocytes and DNA Damage during Chronic Ingestion of Phenolphthalein in Transgenic Female Mice Heterozygous for the p53 Gene ''. Environmental and Molecular Mutagenesis. 31 ( 2 ) : 113 -- 124. doi : 10.1002 / ( SICI ) 1098 - 2280 ( 1998 ) 31 : 2 < 113 : : AID - EM3 > 3.0.CO ; 2 - N. PMID 9544189. Jump up ^ Cooper, G.S. ; Longnecker, M.P. ; Peters, R.K. ( 2004 ). `` Ovarian Cancer Risk and Use of Phenolphthalein - Containing Laxatives ''. Pharmacoepidemiology and Drug Safety. 13 ( 1 ) : 35 -- 39. doi : 10.1002 / pds. 824. PMID 14971121. Jump up ^ Dobrydneva, Y. ; Wilson, E. ; Abelt, C.J. ; Blackmore, P.F. ( 2009 ). `` Phenolphthalein as a Prototype Drug for a Group of Structurally Related Calcium Channel Blockers in Human Platelets ''. Journal of Cardiovascular Pharmacology. 53 ( 3 ) : 231 -- 240. doi : 10.1097 / FJC. 0b013e31819b5494. PMID 19247192. Jump up ^ `` Phenolphthalein - Substance Information - ECHA ''. echa.europa.eu. Retrieved 2017 - 11 - 06. Jump up ^ Baeyer, A. ( 1871 ). `` Ueber eine neue Klasse von Farbstoffen ''. Berichte der Deutschen Chemischen Gesellschaft. 4 ( 2 ) : 555 -- 558. doi : 10.1002 / cber. 18710040209. Jump up ^ Baeyer, A. ( 1871 ). `` Ueber die Phenolfarbstoffe ''. Berichte der Deutschen Chemischen Gesellschaft. 4 ( 2 ) : 658 -- 665. doi : 10.1002 / cber. 18710040247. Jump up ^ Baeyer, A. ( 1871 ). `` Ueber die Phenolfarbstoffe ''. Polytechnisches Journal. 201 ( 89 ) : 358 -- 362. Jump up ^ Max Hubacher, U.S. Patent 2,192,485 ( 1940 to Ex Lax Inc ) Jump up ^ U.S. Patent 2,522,939 External links Wikimedia Commons has media related to Phenolphthalein. Page on different titration indicators, including phenolphthalein Drugs for constipation ( laxatives and cathartics ) ( A06 ) Stool softeners Docusate Stimulant laxatives Bisacodyl Bisoxatin Cascara Castor oil Dantron Oxyphenisatine Phenolphthalein Senna glycosides Sodium picosulfate Bulk - forming laxatives Dietary fiber Ethulose Ispaghula Methylcellulose Polycarbophil calcium Sterculia Triticum Lubricant laxatives Liquid paraffin Mineral oil White petrolatum ( petroleum jelly ) Osmotic laxatives Lactitol Lactulose Laminarid Magnesium carbonate Magnesium citrate Magnesium hydroxide ( milk of magnesia ) Magnesium oxide Magnesium peroxide Magnesium sulfate Mannitol Pentaerythritol Polyethylene glycol ( macrogol ) Sodium phosphate Sodium sulfate Sodium tartrate Sorbitol Enemas Bisacodyl Dantron Glycerol Oil Sodium laurilsulfate Sodium lauryl sulfoacetate Sodium phosphate Sorbitol Opioid antagonists Alvimopan Methylnaltrexone bromide Naloxegol Naloxone ( Oxycodone / naloxone ) Others Linaclotide Lubiprostone Oxyphenisatine Prucalopride Tegaserod Ulimorelin Purine receptor modulators Receptor ( ligands ) P0 ( adenine ) Agonists : 8 - Aminoadenine Adenine P1 ( adenosine ) Agonists : 2 - ( 1 - Hexynyl ) - N - methyladenosine 2 - Cl - IB - MECA 2 ' - MeCCPA 4 ' - O - β - D - Glucosyl - 9 - O - ( 6 ' ' - deoxysaccharosyl ) olivil 5 ' - N - ethylcarboxamidoadenosine Adenosine ADP AMP Apadenoson ATL - 146e ATP BAY 60 -- 6583 Binodenoson Capadenoson CCPA CGS - 21680 CP - 532,903 Evodenoson GR 79236 LUF - 5835 LUF - 5845 N - Cyclopentyladenosine Namodenoson Neladenoson dalanate Piclidenoson Regadenoson SDZ WAG 994 Selodenoson Sonedenoson Tecadenoson UK - 432,097 Antagonists : 8 - Chlorotheophylline 8 - Phenyl - 1, 3 - dipropylxanthine 8 - Phenyltheophylline Acefylline Aminophylline ATL - 444 Bamifylline Cafedrine Caffeine Caffeine citrate Cartazolate CGH - 2466 CGS - 15943 Choline theophyllinate Ciforadenant CPX CVT - 6883 Dimethazan DMPX DPCPX Dyphylline Enprofylline Etazolate Fenethylline IBMX Isovaleric acid Istradefylline KF - 26777 MRE3008F20 MRS - 1220 MRS - 1334 MRS - 1706 MRS - 1754 MRS - 3777 Paraxanthine Pentoxifylline Preladenant Propentofylline Proxyphylline PSB - 10 PSB - 11 PSB - 36 PSB - 603 PSB - 788 PSB - 1115 Reversine Rolofylline SCH - 442,416 SCH - 58261 Theacrine Theobromine Theodrenaline Theophylline Tozadenant Tracazolate VUF - 5574 ZM - 241,385 P2 ( nucleotide ) P2X ( ATP ) Agonists : 2 - Me - SATP α, β - Me - ATP Adenosine ADP AMP Ap4A Ap5A ATP ATPγS BzATP Cibacron blue CTP D - β, γ - Me - ATP GTP HT - AMP Ivermectin L - β, γ - Me - ATP MRS - 2219 PAPET - ATP UTP Zinc Antagonists : 5 - BDBD A-317491 A-438079 A-740003 A-804598 A-839977 AF - 353 AZ - 10606120 AZ - 11645373 BBG Calcium Calmidazolium Chelerythrine Copper Emodin ( Rheum officinale ) Evans Blue Gefapixant GW - 791343 HMA Ip5I isoPPADS JNJ - 47965567 KN - 04 KN - 62 Magnesium MRS - 2159 NF - 023 NF - 110 NF - 157 NF - 279 NF - 449 Opiranserin ( VVZ - 149 ) Oxidized - ATP Phenol Red Phenolphthalein PPADS PPNDS PSB - 12062 Puerarin ( Radix puerariae ) Purotoxin 1 RB - 2 Ro 0437626 Ro 51 RO - 3 Sodium ferulate ( Angelica sinensis, Ligusticum wallichii ) Suramin TC - P 262 Tetramethylpyrazine ( ligustrazine ) ( Ligusticum wallichii ) TNP - ATP Zinc P2Y Agonists : 2 - Me - SADP 2 - Me - SATP 2 - Thio - UTP 5 - Br - UDP 5 - OMe - UDP α, β - Me - ATP Adenosine ADP ADPβS Ap3A AR - C 67085MX ATP ATPγS CTP dATP Denufosol Diquafosol IDP ITP INS - 365 INS - 37217 MRS - 2365 MRS - 2690 MRS - 2693 MRS - 2768 MRS - 2957 MRS - 4062 NF - 546 PAPET - ATP PSB - 0474 PSB - 1114 UDP UDPβS UDP - galactose UDP - glucose UDP - N - acetylglucosamine Up3U UTP UTPγS Antagonists : 2 - Me - SAMP A3P5PS AMPαS Ap4A AR - C 66096 AR - C 67085MX AR - C 69931MX AR - C 118925XX ATP BzATP C1330 - 7 Cangrelor Clopidogrel Elinogrel Ip5I MRS - 2179 MRS - 2211 MRS - 2279 MRS - 2395 MRS - 2500 MRS - 2578 NF - 157 NF - 340 PIT PPADS Prasugrel PSB - 0739 RB - 2 Regrelor Suramin Ticagrelor Ticlopidine UDP Transporter ( blockers ) CNTs 6 - Hydroxy - 7 - methoxyflavone Adenosine dMeThPmR Estradiol KGO - 2142 KGO - 2173 MeThPmR Phloridzin Progesterone ENTs Barbiturates Benzodiazepines Cilostazol Dilazep Dipyridamole Estradiol Ethanol Hexobendine NBMPR Pentoxifylline Progesterone Propentofylline PMAT Decynium - 22 Enzyme ( inhibitors ) XO Allopurinol Amflutizole Benzbromarone Caffeic acid Cinnamaldehyde Cinnamomum osmophloeum Febuxostat Myo - inositol Kaempferol Myricetin Niraxostat Oxipurinol Phytic acid Pistacia integerrima Propolis Quercetin Tisopurine Topiroxostat Others Aminopterin Azathioprine Methotrexate Mycophenolic acid Pemetrexed Pralatrexate Many others Others Precursors : Adenine Adenosine AMP ADP ATP Cytosine Cytidine CMP CDP CTP Guanine Guanosine GMP GDP GTP Hypoxanthine Inosine IMP IDP ITP Ribose Uracil Uridine UMP UDP UTP Others : Chrysophanol ( rhubarb ) See also : Receptor / signaling modulators Retrieved from `` https://en.wikipedia.org/w/index.php?title=Phenolphthalein&oldid=845518280 '' Categories : PH indicators Triarylmethane dyes Phenols IARC Group 2B carcinogens Phthalides Laxatives Hidden categories : Articles with changed DrugBank identifier ECHA InfoCard ID from Wikidata Articles with changed FDA identifier Chembox having GHS data Articles containing unverified chemical infoboxes Chembox image size set Talk Contents About Wikipedia تۆرکجه Беларуская Български Bosanski Català Čeština Dansk Deutsch Eesti Ελληνικά Español Esperanto Euskara فارسی Français 한국어 Հայերեն Hrvatski Bahasa Indonesia Italiano עברית Қазақша Latviešu Lumbaart Magyar Nederlands 日本 語 Norsk Oʻzbekcha / ўзбекча ਪੰਜਾਬੀ Polski Português Română Русский Slovenčina Српски / srpski Srpskohrvatski / српскохрватски Suomi Svenska తెలుగు ไทย Türkçe Українська Tiếng Việt 中文 37 more Edit links This page was last edited on 12 June 2018, at 08 : 29 ( UTC ). 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Question: what is the colour of phenolphthalein in hcl acid
Answer: colorless