What are the common alternative names for phenol?

Phenol is also commonly known by names such as carbolic acid, phenolic acid, and benzenol.

What is the molecular formula and physical state of phenol?

Phenol has the molecular formula C6H6O. It is a white crystalline solid that is volatile and can catch fire.

Describe the basic structure of a phenol molecule.

A phenol molecule consists of a phenyl group, which is a six-membered aromatic ring, directly bonded to a hydroxy group (-OH).

How acidic is phenol, and how does it compare to aliphatic alcohols?

Phenol is mildly acidic, with a pKa of 9.95 in water. It is considered more acidic than aliphatic alcohols due to the resonance stabilization of its conjugate base, the phenolate anion.

What are the primary industrial applications of phenol?

Phenol is a significant industrial commodity, primarily used as a precursor for the large-scale production of plastics and related materials, such as polycarbonates and epoxy resins.

What is the approximate annual global production volume of phenol?

Phenol is produced on a large scale globally, with an estimated annual production of about 7 million tonnes.

What are some key materials and compounds derived from phenol?

Phenol and its derivatives are essential for producing polycarbonates, epoxies, Bakelite, nylon, detergents, herbicides (like phenoxy herbicides), and various pharmaceutical drugs.

What is the CAS number assigned to phenol?

The CAS Registry Number for phenol is 108-95-2.

What are the preferred and systematic IUPAC names for phenol?

The preferred IUPAC name for phenol is simply 'Phenol'. Its systematic IUPAC name is 'Benzenol'.

What is the molar mass of phenol, and what is its melting and boiling point?

Phenol has a molar mass of 94.113 g/mol. It melts at 40.5 °C (104.9 °F) and boils at 181.7 °C (359.1 °F).

How soluble is phenol in water, and how does its sodium salt compare?

Phenol is appreciably soluble in water, with about 8.3 grams dissolving per 100 mL at 20 °C. Its sodium salt, sodium phenoxide, is significantly more soluble in water.

What are the GHS hazard pictograms associated with phenol?

Phenol is associated with the GHS hazard pictograms for corrosion (GHS05), skull and crossbones for toxicity (GHS06), and a silhouette for health hazard (GHS08).

What are the NFPA 704 ratings for phenol regarding health, flammability, and instability?

According to the NFPA 704 system, phenol is rated 3 for health (short exposure could cause serious temporary or residual injury), 2 for flammability (must be moderately heated or exposed to relatively high ambient temperature before ignition), and 0 for instability (normally stable).

What is the flash point of phenol, and what are its explosive limits in air?

Phenol has a flash point of 79 °C (174 °F). Its explosive limits in air are between 1.8% and 8.6%.

What are the reported LD50 (median lethal dose) values for phenol in rats and mice via oral administration?

The LD50 for phenol is reported as 317 mg/kg for rats and 270 mg/kg for mice, both via oral administration.

What are the NIOSH Recommended Exposure Limits (REL) for phenol?

The NIOSH Recommended Exposure Limits (REL) for phenol include a Time-Weighted Average (TWA) of 5 ppm (19 mg/m³) and a Ceiling limit (C) of 15.6 ppm (60 mg/m³) for a 15-minute exposure, with a 'skin' notation indicating potential for significant absorption through the skin.

What is the Immediate Danger to Life or Health (IDLH) concentration for phenol?

The Immediately Dangerous to Life or Health (IDLH) concentration for phenol is 250 ppm.

What is the primary explanation for phenol's acidity compared to aliphatic alcohols?

Phenol's enhanced acidity is primarily attributed to the resonance stabilization of the phenolate anion, where the negative charge is delocalized onto the aromatic ring.

What is the keto tautomer of phenol, and how prevalent is it?

The keto tautomer of phenol is cyclohexadienone. However, this tautomer is nearly negligible, with an equilibrium constant of approximately 10^-13, meaning only a tiny fraction of phenol molecules exist in this form at any given time due to the loss of aromaticity.

How does phenol react with iron(III) chloride?

Phenol and its derivatives react with iron(III) chloride to produce intensely colored solutions that contain phenoxide complexes.

What is the dominant industrial process for producing phenol today?

The dominant industrial process for phenol production, accounting for about 95% of global output, is the cumene process, also known as the Hock process.

What are the main products of the cumene process for phenol production?

The cumene process produces both phenol and acetone as co-products. For the process to be economically viable, there needs to be demand for both chemicals.

What is the older commercial route for phenol production that involves benzenesulfonic acid?

An older commercial route, developed in the early 1900s, involved reacting benzenesulfonic acid with a strong base to form sodium phenoxide, followed by acidification to yield phenol. The net reaction is C6H5SO3H + 2 NaOH → C6H5OH + Na2SO3 + H2O.

How can chlorobenzene be converted to phenol, and what are the associated drawbacks?

Chlorobenzene can be hydrolyzed to phenol using either a base (the Dow process) or steam (the Raschig–Hooker process). The drawbacks of these methods include the cost of chlorobenzene and the need to manage the chloride byproduct.

Besides industrial production, is phenol found naturally?

Yes, phenol is a normal metabolic product found in human urine. It has also been detected in the temporal gland secretion of male elephants during musth and in castoreum, a substance produced by beavers.

In what type of alcoholic beverage is phenol a notable flavor component?

Phenol is a measurable component contributing to the aroma and taste of Islay Scotch whisky, typically found at concentrations around 30 ppm.

What bacterium species is known to degrade phenol as its sole carbon source?

Rhodococcus phenolicus is a species of bacterium capable of degrading phenol, using it as its only source of carbon.

What is the significance of the term 'phenol' beyond the specific molecule?

The term 'phenol' is also used more broadly to classify any organic compound that features a six-membered aromatic ring directly attached to a hydroxyl group (-OH).

Who discovered phenol, and from what source was it initially isolated?

Phenol was discovered in 1834 by Friedlieb Ferdinand Runge, who isolated it in an impure form from coal tar. He initially named it 'Karbolsäure', or carbolic acid.

Who first used phenol as an antiseptic in surgery, and what inspired this application?

Sir Joseph Lister pioneered the use of phenol as an antiseptic in surgery. His work was inspired by Louis Pasteur's research on sterilization and the observed effectiveness of carbolic acid in reducing the smell from sewage treatment.

What was the impact of Lister's antiseptic surgery using phenol on patient mortality rates?

Before Lister introduced antiseptic surgery, the hospital's mortality rate for surgical cases was nearly 50%. After its introduction, the mortality rate dropped significantly to around 15%, marking a remarkable improvement in patient outcomes.

How was phenol used by Nazi Germany during World War II?

During World War II, phenol was used by Nazi Germany as a method for individual execution, particularly in programs like Aktion T4 for disabled people and in concentration camps like Auschwitz, where injections of phenol were administered to thousands.

What are the potential health hazards associated with skin contact with phenol?

Phenol is corrosive and can cause severe skin burns. Repeated or prolonged contact can lead to dermatitis or chemical burns, and significant absorption through the skin can cause systemic poisoning, potentially affecting the liver, heart, and central nervous system.

What methods are recommended for decontaminating phenol from skin exposure?

Skin exposures to phenol can be decontaminated by washing with polyethylene glycol, isopropyl alcohol, or by using copious amounts of water.

What is bisphenol-A, and how is it related to phenol?

Bisphenol-A is a key precursor for polycarbonates and epoxy resins. It is synthesized through the condensation reaction of phenol with acetone.

What are phenolic resins, and what is a well-known example?

Phenolic resins are produced by the condensation of phenol (or related compounds like alkylphenols and diphenols) with formaldehyde. Bakelite is a famous example of a phenolic resin.

How is phenol used as a chemical denervation agent?

Phenol is used in analgesia treatments, such as for spasticity, arthritis, or cancer pain, by injecting it to denervate nerves. It works by denaturing proteins and affecting nerve fat and myelin, thereby interrupting sensory transmission.

What recent clinical studies have shown effectiveness for phenol injections in knee pain?

Clinical studies from 2023-2025 reported that injecting phenol into sensory knee nerves was effective as a neurolytic treatment for pain associated with chronic osteoarthritis, particularly for patients who did not find relief from other treatments like radiofrequency ablation.

What is the role of phenol in the phenol-chloroform extraction technique?

Phenol is a component in the phenol-chloroform extraction technique, which is used in molecular biology to isolate nucleic acids (DNA or RNA) from tissues or cell samples.

How is phenol used in otology procedures?

Concentrated liquid phenol can be applied topically as a local anesthetic during otology procedures, such as myringotomy and the placement of tympanotomy tubes, as an alternative to general anesthesia.

What is the mechanism behind phenol's corrosive effect on skin?

Phenol's corrosive action on skin and mucous membranes is due to its ability to denature proteins.

What is the primary reason cited for phenol's enhanced acidity compared to aliphatic alcohols?

The primary reason for phenol's greater acidity is the resonance stabilization of the phenolate anion, which distributes the negative charge across the aromatic ring.

What is the typical concentration of phenol in Islay Scotch whisky, and what does it contribute to?

Phenol is typically found at around 30 ppm in Islay Scotch whisky and contributes to its distinctive aroma and taste.

What is the purpose of nitrogen-blanketing when shipping phenol?

Nitrogen-blanketing is used during the shipping of phenol, typically in a molten state, to prevent discoloration.

What are the primary uses of phenol that consume the largest portion of its production?

The major uses of phenol, consuming about two-thirds of its production, involve its conversion into precursors for plastics, such as bisphenol-A for polycarbonates and epoxy resins, and formaldehyde for phenolic resins.

What is the reaction of phenol with diazomethane in the presence of boron trifluoride?

When phenol reacts with diazomethane in the presence of boron trifluoride (BF3), the primary product formed is anisole, with nitrogen gas as a byproduct.

What is the significance of the 'skin' notation associated with NIOSH exposure limits for phenol?

The 'skin' notation indicates that phenol can be significantly absorbed through the skin, contributing to overall exposure. Therefore, skin protection is crucial when working with phenol.

How does phenol's reactivity with nitric acid differ based on concentration?

Phenol reacts with dilute nitric acid at room temperature to form a mixture of 2-nitrophenol and 4-nitrophenol. With concentrated nitric acid, further substitution occurs, leading to compounds like 2,4,6-trinitrophenol (picric acid).

What is the role of Joseph Lister in the history of phenol?

Sir Joseph Lister was a pioneer in antiseptic surgery and famously used phenol (carbolic acid) to sterilize wounds and surgical sites, significantly reducing infection rates and improving patient survival.

What is the 'carbolic smoke ball' mentioned in relation to phenol's history?

The 'carbolic smoke ball' was an ineffective device marketed in London during the 19th century, claimed to protect against influenza and other ailments. It became the subject of the notable legal case *Carlill v Carbolic Smoke Ball Company*.

Phenol Wiki: Phenol: The Aromatic Hydroxyl Compound

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Fundamental Properties

Appearance & State

Phenol is a transparent crystalline solid at standard conditions. It possesses a characteristic sweet and tarry odor.

Thermal Properties

It has a melting point of 40.5 °C (104.9 °F) and a boiling point of 181.7 °C (359.1 °F). Phenol is combustible, with a flash point of 79 °C (174 °F).

Solubility & Density

Phenol is appreciably soluble in water, forming homogeneous mixtures under certain conditions. Its density is approximately 1.07 g/cm³.

Reactivity & Acidity

It is a weak acid (pKa ≈ 9.95 in water) and is highly reactive towards electrophilic aromatic substitution due to the activating hydroxyl group.

Acidity and Resonance

Weak Acidic Nature

Phenol is classified as a weak acid. In aqueous solutions, it can deprotonate to form the phenoxide anion (C₆H₅O⁻). This acidity is greater than that of aliphatic alcohols due to the stabilization of the phenoxide ion.

Resonance Stabilization

The negative charge on the phenoxide anion is delocalized into the aromatic ring through resonance. This electron delocalization stabilizes the anion, making phenol more acidic than alcohols where such resonance is not possible.

The delocalization of the negative charge onto the ortho and para positions of the benzene ring significantly lowers the energy of the phenoxide ion compared to the neutral phenol molecule. This stabilization effect is a key factor contributing to phenol's acidity.

Hydrogen Bonding

Phenol can participate in hydrogen bonding with various Lewis bases. It is categorized as a "hard acid" in the context of the Hard and Soft Acids and Bases (HSAB) theory.

Industrial Production

The Cumene Process

The dominant industrial method for phenol production is the cumene process (or Hock process). This involves the oxidation of cumene (isopropylbenzene) followed by acid-catalyzed rearrangement (Hock rearrangement) to yield phenol and acetone as a co-product.

The cumene process is favored for its efficiency and use of readily available petrochemical feedstocks. It accounts for approximately 95% of global phenol production. The economic viability relies on the demand for both phenol and its co-product, acetone.

Older and Alternative Methods

Historically, phenol was extracted from coal tar. Other methods include the hydrolysis of chlorobenzene (Dow process, Raschig–Hooker process) and the hydrolysis of benzenesulfonic acid. These older methods are less common today due to cost or environmental considerations.

Diverse Applications

Polymer Precursor

Phenol is a critical intermediate in the synthesis of plastics and resins. It is used to produce bisphenol-A (for polycarbonates and epoxy resins) and phenolic resins (like Bakelite) through condensation reactions with formaldehyde.

Pharmaceuticals and Chemicals

It serves as a precursor for numerous pharmaceuticals, including aspirin. Phenol derivatives are also used in the production of detergents, herbicides, and explosives.

Medical Applications

Phenol has applications as a topical anesthetic and antiseptic. It is used in some pain relief formulations and for procedures like ingrown toenail treatment. It also serves as a chemical agent for nerve blocks to manage pain.

Hazards and Toxicity

Corrosive and Toxic

Phenol is a highly corrosive and toxic substance. Exposure can cause severe chemical burns upon skin contact and systemic poisoning if ingested, inhaled, or absorbed through the skin.

GHS and NFPA Ratings

Globally Harmonized System (GHS) labeling indicates danger, with hazards including toxicity if swallowed, inhaled, or in contact with skin, and causing severe skin burns and eye damage. The NFPA 704 rating highlights health (3), flammability (2), and instability (0).

Key GHS Hazard Statements include H301 (Toxic if swallowed), H311 (Toxic in contact with skin), H314 (Causes severe skin burns and eye damage), H331 (Toxic if inhaled), H341 (Suspected of causing genetic defects), and H373 (May cause damage to organs through prolonged or repeated exposure).

Health Effects

Symptoms of exposure can range from central nervous system depression (coma, seizures) to hemolytic anemia, cardiac arrhythmias, and pulmonary edema. Chronic exposure may lead to kidney toxicity and skin lesions.

Historical Significance

Discovery and Early Use

Phenol was first isolated from coal tar in 1834 by Friedlieb Ferdinand Runge. Its potent antiseptic properties were later utilized by Sir Joseph Lister in the development of antiseptic surgery, significantly reducing surgical mortality.

Industrial Evolution

Initially sourced from coal tar, phenol production shifted to petrochemical feedstocks with the development of processes like the cumene process. This transition enabled large-scale industrial availability.

Wartime Use

During World War II, phenol was infamously used by Nazi Germany as a method of execution due to its rapid toxicity.

Natural and Other Occurrences

Metabolic and Biological

Phenol is a normal metabolic product found in human urine. It has also been detected in the temporal gland secretions of male elephants during musth and in castoreum, a secretion from beavers.

Flavor Component

Phenol is a measurable component contributing to the characteristic smoky aroma and taste of certain Scotch whiskies, particularly those from the Islay region, derived from the peat used in malting barley.

Nomenclature

Chemical Identity

The IUPAC preferred name is Phenol. It is also commonly known as carbolic acid, benzenol, or phenyl alcohol. The term "phenol" also refers to any compound containing a hydroxyl group directly attached to an aromatic ring.

Etymology

The name "phenol" originates from the Greek word "phainein" (to shine or illuminate), related to benzene's presence in illuminating gas. The term "carbolic acid" derives from its origin in coal tar ("coal-oil-acid").

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References

Sigma-Aldrich Co., Phenol. Retrieved on 2022-02-15.

Laurence, C. and Gal, J-F. Lewis Basicity and Affinity Scales, Data and Measurement, (Wiley 2010) pp 50-51 ISBN 978-0-470-74957-9

Wittcoff, H.A., Reuben, B.G. Industrial Organic Chemicals in Perspective. Part One: Raw Materials and Manufacture. Wiley-Interscience, New York. 1980.

Franck, H.-G., Stadelhofer, J.W. Industrial Aromatic Chemistry. Springer-Verlag, New York. 1988. pp. 148-155.

The Experiments by Peter Tyson. NOVA

The Beaver: Its Life and Impact. Dietland Muller-Schwarze, 2003, page 43 (book at google books)

A full list of references for this article are available at the Phenol Wikipedia page

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This page was generated by an Artificial Intelligence and is intended for informational and educational purposes only. The content is based on publicly available data and may not be entirely accurate, complete, or up-to-date.

This is not chemical or safety advice. The information provided on this website is not a substitute for professional consultation regarding chemical handling, safety protocols, or industrial applications. Always refer to official safety data sheets (SDS), regulatory guidelines, and consult with qualified chemical safety professionals for specific needs.

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Phenol: The Aromatic Hydroxyl Compound

💡 Dive in with Flashcard Learning! 💡

Fundamental Properties 🧪

💎 Appearance & State

🌡️ Thermal Properties

💧 Solubility & Density

⚡ Reactivity & Acidity

Acidity and Resonance ⚖️

⚛️ Weak Acidic Nature

🔄 Resonance Stabilization

🔗 Hydrogen Bonding

Industrial Production 🏭

➡️ The Cumene Process

⏳ Older and Alternative Methods

Diverse Applications 💡

🏗️ Polymer Precursor

💊 Pharmaceuticals and Chemicals

⚕️ Medical Applications

Hazards and Toxicity ☠️

⚠️ Corrosive and Toxic

🚨 GHS and NFPA Ratings

🩹 Health Effects

Historical Significance 📜

🔍 Discovery and Early Use

🏭 Industrial Evolution

⚔️ Wartime Use

Natural and Other Occurrences 🌍

🌿 Metabolic and Biological

🥃 Flavor Component

Nomenclature 🏷️

📚 Chemical Identity

💡 Etymology

Teacher's Corner 🧑‍🏫

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📜 Important Notice

Dive in with Flashcard Learning!

Fundamental Properties

Appearance & State

Thermal Properties

Solubility & Density

Reactivity & Acidity

Acidity and Resonance

Weak Acidic Nature

Resonance Stabilization

Hydrogen Bonding

Industrial Production

The Cumene Process

Older and Alternative Methods

Diverse Applications

Polymer Precursor

Pharmaceuticals and Chemicals

Medical Applications

Hazards and Toxicity

Corrosive and Toxic

GHS and NFPA Ratings

Health Effects

Historical Significance

Discovery and Early Use

Industrial Evolution

Wartime Use

Natural and Other Occurrences

Metabolic and Biological

Flavor Component

Nomenclature

Chemical Identity

Etymology

Teacher's Corner

True or False?

Test Your Knowledge!

Gamer's Corner

Discover other topics to study!

References

Feedback & Support

Disclaimer

Important Notice