Certain features of will be unavailable due to maintenance from saturday morning, april 25th at 9. Inhalation of phenol vapor may cause lung problems. The nomenclature would be phenol2,4disulphonic acid n. Why is this a better method than simply treating phenol with concentrated nitric acid to obtain picric acid. Its synthesis from phenol, and the correct determination of its formula, were successfully accomplished in 1841. If you decide to dispose of your wet picric acid, some options are available. This a yellow crystalline solid is one of the most acidic phenols. Phenols and phenolic compounds picric acid manufacturer. Phenol is highly irritating to the skin, eyes, and mucous membranes in humans after acute. Picric acid is the chemical compound more formally called 2,4,6trinitrophenol tnp.
The dry compound can explode if shocked or exposed to heat. Phenol, c 6 h 5 oh when it first reacts with concentrated sulphuric acid, forms y. Recommendations for immediate medical carespecial treatment. Initially, it was made by nitrating substances such as animal horn, silk, indigo, and natural resin, the synthesis from indigo first being performed by peter woulfe in 1771.
Like other highly nitrated organic compounds, picric acid is an explosive, hence its primary use. Picric acid is an organic compound with the formula o2n3c6h2oh. Phenol structure phenol is an aromatic alcohol the oh group is attached directly to the benzene ring it is an almost colourless crystalline solid of formula c6h5oh preparation you cannot put an oh group directly onto a benzene ring by electrophilic substitution phenol is synthesised in a multistage process. When added with water, this effective chemical acts as a desensitizer. Pipette 10 ml of the sample into a 100 ml volumetric flask. Preparation you cannot put an oh group directly onto benzene by electrophilic substitution phenol can be synthesised in a multistage process nitration of benzene reagents conc. The complexes with aromatic hydrocarbons, etc, are in general not so sensitiv the frictionsensitivecalcium salt. Phenol no 2 picric acid 2,4,6trinitrophenol ch 3 ch 3 conc. Preparation of phenol by benzene sulphonic acid duration.
Phenol reacts with dilute nitric acid at room temperature to give a mixture of 2nitrophenol and 4nitrophenol while with concentrated nitric acid, more nitro groups get substituted on the ring to give 2,4,6trinitrophenol which is known as picric acid. Picric acid, saturated aqueous solution, approximately 1. Onestep synthesis of picric acid from phenol article pdf available in organic preparations and procedures international 492. As an acid, contact with metals form picrate salts, nearly of all which are energetic to some degree. Burns if ignited by a flame and continues to burns quietly if the quantity is small or, if large, is thinly spread over an area. My textbook says nowadays picric acid is prepared by treating phenol first with concentrated sulfuric acid which converts it to phenol2,4disulfuric acid and then with concentrated nitric acid to. Offered chemical is pale yellow and odorless, with slight solubility in water.
This yields phydroxyphenylsulphonic acid which can then be nitrated using conc nitric acid. Picric acid is a cnitro compound comprising phenol having three nitro substtituents at the 2, 4 and 6positions. Picric acid was the first high explosive nitrated organic compound widely considered suitable to withstand the shock of firing in conventional artillery. As part of your lab inspection program, check the hydration of your picric acid at least every six months and add distilled water as necessary. These metrics are regularly updated to reflect usage leading up to the last few days. Picric acid is a phenolic compound, also known as 2,4,6trinitrophenol. It has a role as an explosive, an antiseptic drug and a fixative.
Preparation of ethers by acid dehydration of secondary or tertiary alcohols is not a suitable method. Formation of hydridemeisenheimer complexes of picric acid 2,4,6. Picric acid is a cnitro compound comprising phenol having three nitro substtituents at. Be sure to clean the bottleneck, cap and threads with a wet cloth before resealing 16.
Making use of phenols high water solubility, and the higher solubility of dinitro and mononitrophenol, the picric acid can be purified to near analytical grade by recrystallization from a solvent mixture of 1 volume ethanol and 2 volumes water, roughly 9ml of solvent being required per gram of picric acid. Picric acid can be found on the following state righttoknow lists. Picric acid, wet, with not less than 10% water undergoes vigorous reactions with both oxidizing or reducing agents. Do not place in metal containers or containers with metal lids. Used in synthesis of dyes, as a drug, to manufacture explosives and matches, to etch copper and. Information on picric acid stanford environmental health. Picric acid is 2,4,6trinitrophenol i synthesised it from phenol. Backed by a team of experienced professionals, we are involved in the manufacture and supply of picric acid. Picric acid, wetted 88 89 1 ec50 other aquatic organisms 1 240 mgl algae.
Picric acid 10 was probably first mentioned in the alchemical writings of johann rudolf glauber in 1742. Picric acid forms salts with manymetals some of which are rather sensitiv nickel, copper, etc. Khabarov and others published onestep synthesis of picric acid from phenol find, read and cite all the. Picric acid, 2,4dnp, 2nitrophenol, 4nitrophenol, 4nitrocatechol, phenol, 2. To get round this, sulphonation of anhydrous phenol is carried out uisng fuming sulfuric acid.
Picric acid material safety data sheet cas no 88891. Phenol 108952 hazard summary exposure to phenol may occur from the use of some medicinal products including throat lozenges and ointments. Like other highly nitrated organic compounds, picric acid is an explosive, which was once its primary use. Picric acid was used in the quantitative determination of bisoprolol. Dry mixtures of picric acid and alum ignition after a delay dependent upon the quantity. This causes the displacement of the sulphonic group and the introduction of nitro groups which yield the required product picric acid 2,4,6trinitrophenol. Picric acid is also used in the analytical chemistry of metals, ores, and minerals. If possible, eliminate solid picric acid from your inventory by purchasing premixed stains or a 1% solution for use in stain preparation. The picric acid method for determining weak acid dissociable wad cyanide 3 8. Picric acid should be disposed as a hazardous waste within 2 years of initial receipt.
Picric acid understanding specific chemicals hazard prevor. Pdf onestep synthesis of picric acid from phenol researchgate. Identify y and z and explain why phenol is not converted commercially to z by reacting it with conc. Picric acid is obtained by nitration of phenol by concentrated hno3 in presence of concentrated h2so4. Picric acid is an organic acid, and will react with many metals and bases to form salts known as picrates, which are more sensitive than picric acid itself, as well as forming a few complexes.
Picric acid page 4 of incident management physicochemical properties cas number 88891 molecular weight 229. It is used as a high explosive, an oxidant in rocket fuels, in matches and leather processing, in dyes, as a laboratory reagent for serum creatinine analysis in humans and experimental animals, other laboratory uses, metal etching, batteries, as a textile mordant, in manufacture of colored glass, and in the production of picramic acid and. What is picric acid and why 2,4,6 trinitro phenol is. Picric acid, wetted 88 89 1 persistence and degradability not readily biodegradable in water. Picric acid finds a major usage in laboratories, as a chemical reagent. Publication processes organization and format errata, author corrections. How will you prepare picric acid from phenol industrially. The preparation and properties of picric acid youtube. The name picric comes from the greek pikros, meaning bitter, reflecting its bitter taste. For safety transportation, 30% water or more is usually added. Picric acid safety guidelines concordia university. Aqueous solutions of phenol are weakly acidic and turn blue litmus slightly to red. Picric acid was probably first mentioned in the alchemical writings of johann rudolf glauber in 1742. Picric acid has been used in the preparation of bouin.
Every couple months, an article appears in the local paper about a bomb disposal team removing picric acid that was found in a laboratory. In this video, picric acid secondary explosive is prepared by the reaction of aspirin acetylsalicylic acid with potassium nitrate in the presence of. Picric acid understanding specific chemicals hazard. If possible, eliminate it from your inventory by purchasing premixed stains or a 1 % solution for using in stain preparation. An improved spectrophotometric assay of hydrocyanic acid and cyanide ions with picric acid and resorcinol is described. In preliminary studies, we were able to establish that the direct synthesis of picric. Y is reacted with concentrated nitric acid to form z. Make sure that any picric acid disposed of still has some water content. Picric acid forms salts with many metals some of which are rather sensitive to heat, friction, or impact, e.
Initially, it was made by nitrating substances such as animal horn, silk, indigo, and natural resin. My textbook says nowadays picric acid is prepared by treating phenol first with concentrated sulfuric acid which converts it to phenol2,4disulfuric acid and then with concentrated nitric acid to get 2,4,6trinitrophenol my question. Its name comes from greek bitter, reflecting the bitter taste of picric acid. Besides this, it decomposing carbonates like another acid and the pka value of 2,4,6trinitro phenol is 0. It has also been used in medicine antiseptic, burn treatments and dyes. Purchases of picric acid should be restricted to the smallest practical quantities. Picric acid is a chemical compound formally called 2,4,6trinitrophenol tnp. Organic conversion phenol to picric acid tx academy.
Preparation of ethers by acid dehydration of secondary or. Persistence and degradability picric acid, saturated persistence and degradability not established. Like other highly nitrated compounds such as tnt, picric acid is an explosive. The nomenclature would be phenol2,4disulphonic acidn.