Picric acid from phenol

In this explainer, we will learn how to describe the physical and chemical properties of phenol. Phenols are a class of aromatic molecules that contain a hydroxy ( O H) group bonded directly to an aromatic ring. The presence of an O H group suggests that phenols are a type of alcohol. However, the physical and chemical properties of phenols differ from those of aliphatic alcohols. Often, phenol refers to the simplest hydroxy aromatic molecule where a single hydroxyl group is bonded to a benzene ring. The structure of phenol, also known as carbolic acid or hydroxybenzene, is shown below. Phenols are of great importance in pharmaceutical industries. For example, salicylic acid (the precursor to aspirin), paracetamol, and vanillin, shown below, are all examples of phenol compounds. Phenolic compounds are commonly used as the starting point for synthesizing a wide array of important compounds. Definition: Phenols A class of organic molecules with a hydroxy group bonded directly to an aromatic ring. Phenol, with the chemical formula C H O H 6 5, is a white solid that has a smell similar to that of a disinfectant. Care must be taken when handling solid phenol as it can be corrosive to the skin. The melting point of phenol ( ∼ 4 0 . 5 ) ∘ C is much higher than those of benzene and methylbenzene (toluene). Phenol is reasonably soluble in water, much more soluble than benzene and methylbenzene. Both these properties of phenol can be mostly attributed to hydrogen bonding that can oc...

Conversion of Phenol to Picric acid:- Step 1: Formation of Picric acid When the Phenol is treated with concentrated Nitric acid snd concentrated sulphuric acid, Picric( 2 , 4 , 6 - trinitrophenol) acid is formed: This conversion of Phenol to Picric acid is a 1 step reaction. Therefore, Phenol when treated with concentrated Nitric acid and Sulphuric acid, Picric acid is formed.

Phenols Physical properties of phenol Phenol is a solid corrosive substance, It has a characteristic odour, its melting point is 43°C and its boiling point is 182°C, It is sparingly soluble in Chemical properties of phenol The acidic properties are attributed to the presence of hydrogen ion, Both The polarity of (O−H) bond increases in phenols as the benzene ring in phenol increases the polarity which makes the bond (O−H) longer and weaker which facilitate the separation of hydrogen ion , that is why phenol reacts with the alkalis like caustic soda and this doesn’t take place in Ethanol reacts with hydrochloric acid while phenol doesn’t react because hydroxyl group is removed easily from The acidity of phenol is more than that of ethanol because the benzene ring increases the length of (O−H) bond and weakens it, so the hydrogen ion is separated easily while the alkyl group of +. The reaction of phenol with acetic acid: CH 3COOH + HOC 6H 5 → CH 3COOC 6H 5 + H 2O Reaction specific to the hydroxyl group: Phenols do not react with HX in normal conditions due to the strong bond between carbon of the Reaction specific to the carbinol group: Phenol does not oxidize chemically. Reaction specific to benzene ring Nitration: Phenols reacts with concentrated nitric acid in the presence of conc. H 2SO 4 to form 2,4,6-tri-nitro phenol which is known commercially as picric acid, Picric acid is used in the manufacture of explosives, treatment of burns, It gives the skin a yellow colour, w...

• Afrikaans • العربية • Azərbaycanca • تۆرکجه • বাংলা • Беларуская • Български • Чӑвашла • Čeština • Dansk • Deutsch • Eesti • Ελληνικά • Español • Esperanto • Euskara • فارسی • Français • Gaeilge • 한국어 • Հայերեն • हिन्दी • Hrvatski • Ido • Íslenska • Italiano • ქართული • Kaszëbsczi • Қазақша • Кыргызча • Latviešu • Lietuvių • Magyar • മലയാളം • Bahasa Melayu • Nederlands • 日本語 • Norsk bokmål • Oʻzbekcha / ўзбекча • Polski • Português • Română • Русский • Slovenčina • Slovenščina • Српски / srpski • Srpskohrvatski / српскохрватски • Suomi • Svenska • தமிழ் • Türkçe • Українська • Tiếng Việt • 中文 Chemical compound Picric acid is an 2N) 3C 6H 2OH. Its 2,4,6-trinitrophenol ( TNP). The name "picric" comes from πικρός ( pikros), meaning "bitter", due to its bitter taste. It is one of the most History [ ] Picric acid was probably first mentioned in the Kohlenstickstoffsäure (rendered in French as acide carboazotique). Picric acid was given that name by the French chemist Picric acid was the first strongly explosive nitrated Melinite. In 1888, Britain started manufacturing a very similar mixture in Lyddite. Japan followed with an alternative stabilization approach known as Dunnite or Picric acid was used in the Efforts to control the availability of [ citation needed] Synthesis [ ] The aromatic ring of p-hydroxyphenylsulfonic acid is then nitrated with concentrated Pca2 1 with a = 9.13 Å, b = 18.69 Å, c = 9.79 Å and α = β = γ = 90°. Uses [ ] By far the greatest use of picric acid ...

https://chem.libretexts.org/@app/auth/3/login?returnto=https%3A%2F%2Fchem.libretexts.org%2FBookshelves%2FOrganic_Chemistry%2FMap%253A_Organic_Chemistry_(Vollhardt_and_Schore)%2F22%253A_Chemistry_of_the_Benzene_Substituents%253A_Alkylbenzenes_Phenols_and_Benzenamines%2F22.03%253A_Names__and__Properties_of_Phenols Compounds like alcohols and phenol which contain an -OH group attached to a hydrocarbon are very weak acids. Alcohols are so weakly acidic that, for normal lab purposes, their acidity can be virtually ignored. However, phenol is sufficiently acidic for it to have recognizably acidic properties - even if it is still a very weak acid. A hydrogen ion can break away from the -OH group and transfer to a base. Why is phenol acidic? Compounds like alcohols and phenol which contain an -OH group attached to a hydrocarbon are very weak acids. Alcohols are so weakly acidic that, for normal lab purposes, their acidity can be virtually ignored. However, phenol is sufficiently acidic for it to have recognizably acidic properties - even if it is still a very weak acid. A hydrogen ion can break away from the -OH group and transfer to a base. For example, in solution in water: Phenol is a very weak acid and the position of equilibrium lies well to the left. Phenol can lose a hydrogen ion because the phenoxide ion formed is stabilised to some extent. The negative charge on the oxygen atom is delocalised around the ring. The more stable the ion is, the more likely it is to form. One ...

\( \newcommand\) • Substitution of the hydroxyl hydrogen atom is even more facile with phenols, which are roughly a million times more acidic than equivalent alcohols. This phenolic acidity is further enhanced by electron-withdrawing substituents ortho and para to the hydroxyl group, as displayed in the following diagram. The alcohol cyclohexanol is shown for reference at the top left. It is noteworthy that the influence of a nitro substituent is over ten times stronger in the para-location than it is meta, despite the fact that the latter position is closer to the hydroxyl group. Furthermore additional nitro groups have an additive influence if they are positioned in ortho or para locations. The trinitro compound shown at the lower right is a very strong acid called picric acid. Why is phenol a much stronger acid than cyclohexanol? To answer this question we must evaluate the manner in which an oxygen substituent interacts with the benzene ring. As noted in our earlier treatment of electrophilic aromatic substitution reactions, an oxygen substituent enhances the reactivity of the ring and favors electrophile attack at ortho and para sites. It was proposed that resonance delocalization of an oxygen non-bonded electron pair into the pi-electron system of the aromatic ring was responsible for this substituent effect. Formulas illustrating this electron delocalization will be displayed when the "Resonance Structures" button beneath the previous diagram is clicked. A similar s...

Overview - Aqueous vs Organic Solvents In aqueous solutions, phenols are weakly acidic and lower the pH of a solution. Sodium hydroxide can be used to fully deprotonate a phenol. Water soluble alcohols do not change the pH of the solution and are considered neutral. Aqueous solutions of sodium hydroxide can not deprotonate alcohols to a high enough concentration to be synthetically useful. In solutions of organic solvents, more extreme reaction conditions can be created. Sodium metal can be added to an alcohol in an organic solvent system to fully deprotonate the alcohol to form alkoxide ions. Acid/Base properties of alcohols Several important chemical reactions of alcohols involving the O-H bond or oxygen-hydrogen bond only and leave the carbon-oxygen bond intact. An important example is salt formation with acids and bases. Alcohols, like water, are both weak bases and weak acids. The acid ionization constant (Ka) of ethanol is about 10~18, slightly less than that of water. Ethanol can be converted to its conjugate base by the conjugate base of a weaker acid such as ammonia {Ka — 10~35), or hydrogen (Ka ~ 10-38). It is convenient to employ sodium metal or sodium hydride, which react vigorously but controllably with alcohols: The order of acidity of various liquid alcohols generally is water > primary > secondary > tertiary ROH. By this we mean that the equilibrium position for the proton-transfer reaction (Equation 15-1) lies more on the side of ROH and OHe as R is change...