Phenol

Phenol is a common name in the world of organic chemistry. The chemical formula of phenol is C6H6O. C6H6O is an aromatic compound, which means it forms a ring and contains 4n+2 double bonds. The compound has a hydroxyl group attached to a phenyl group. It is adequately soluble in water and found use as a cleansing agent. Phenol indeed was one of the first organic compounds used in industrially produced soap. In water, it is mildly acidic and is even corrosive to body parts such as the eyes, respiratory tract and the skin. Due to these reasons, phenol lost its application as a cleanser. 

In this segment, we are going to learn several things about phenol. We will focus on phenol structure; we will understand the formula of phenol better by opening up its structure, we will know the uses of phenol and the chemical properties of phenol. We will also breeze through some physical properties such as the molecular weight of phenol, and we will look into reactions of phenols and the phenol formula. However, before all that, we need a little more detailed introduction to this unique compound.


What Is Phenol?

So, as we know, phenol is an aromatic compound. But who discovered it and how? Phenol was found by a scientist named Friedlieb Ferdinand Runge in the year 1834. He managed to extract it from coal tar. It is a crystalline solid which is white. Phenol needs proper care when handled because it can cause chemical burns to the skin. Another name for this compound if phenolic acid. The way to identify a member of this species is to look for a six-membered aromatic ring which is directly attached to a hydroxyl group. Such a species is part of the phenol family and has the formula of phenol. So, now that you know s and the phenol formula, we can move onto some other details about this compound family.

 

Physical Properties Of Phenol

Listed below are some physical properties of phenol. Once we go through these, we will explore the chemical properties of phenol. Some key details regarding this heteroatom are:

  • Boiling point: 181.7 °C

  • Melting point: 40.5 °C

  • Density: 1.07 g/cm³

  • The molecular weight of phenol: 94.11 g/mol

 

Chemical Properties Of Phenol

Here we will discuss the specific chemical properties of phenol. We will first unlock the phenol structure and phenol formula. After that, we will go through particular reactions of phenol. 


Phenol Structure

The following image will give you a clear idea of the phenol structure.

(Image to be added soon)

Phenol structure: C6H6O

We have both an animated model as well as a chemically represented phenol ring. If you study the structures, you will adequately understand the phenol structure. 


Reactions Of Phenol

Phenols are super reactive because a hydroxyl group attached to an aromatic ring is an influential ortho-para director. Therefore, phenol has an excellent affinity towards electrophilic aromatic substitution in its ortho and para carbons. 

  1. Reactions involving the phenol ring: The hydroxyl group in the phenyl ring causes an increased ortho-para carbon reactivity in the species. Therefore, phenol undergoes electrophilic substitution reactions.

  2. Halogenation of phenol: The - OH group is so reactive that phenol undergoes poly substitution frequently. The reaction should take place in a nonpolar solvent such as CS2 or CCl4 and at low temperature to prevent poly substitution.


How Is Phenol Made?

Scientists achieve a unique phenol structure using several reactions. They probe the formula of phenol and find out ways to accomplish that particular arrangement of atoms. Two methods of synthesis to make the phenol structure and phenol formula are:

  1. From sulphuric acid:

C6H5SO3Na + 2 NaOH → C6H5ONa + Na2SO3 + H2O

2C6H5ONa + 2 HCl → 2C6H5OH + 2 NaCl

  1. From diazonium salts:

ArN2X + H2O → Ar-OH + N2 + HX

C6H5N2Cl + H2O → C6H5OH + N2 + HCL

Now we will move onto the uses of phenol.


Uses Of Phenol

There are several uses of phenol. We are listing some below:

  • Phenol is present in drugs.

  • It is an antiseptic.

  • It helps in the production of nylon.

  • Phenol preserves vaccines.

  • Oral analgesics implement phenols.

Now that we know the uses of phenol and enough about the formula of phenol, we will delve into some solved examples. 


Solved Examples

  1. Why are phenols more soluble in water than alcohols?

Ans: Phenols form stronger hydrogen bonds than alcohols. Therefore, they dissolve better in water.

  1. Arrange the following in terms of decreasing boiling points: isobutyl alcohol, tert-Butyl alcohol, butan-1-ol

Ans: Due to intermolecular hydrogen bonding, the boiling point of phenols is considerably high. The compounds, arranged in the form of decreasing boiling points are as below:

tert-Butyl alcohol < isobutyl alcohol < butan-1-ol


Fun Facts

  • Phenol is pretty low in cost, and therefore many industries tend to use it in their manufacturing process.

  • Phenols find application in several household products. They are present in detergents and household cleaners and even in mouthwashes.

  • Phenol was one of the first organic species which found application as a surgical disinfectant. Surgeons used it to kill germs in a surgical procedure.

FAQ (Frequently Asked Questions)

1. What is the Nature of Phenol? Is it Acidic or Basic?

Phenols are slightly acidic. However, they are much more acidic than aliphatic organic compounds. The reason for the acidity of phenols is the phenol formula. 

It consists of a phenyl ring with an attached hydroxyl group. The OH group makes it a monobasic acid. Also, the aromatic ring resonance stabilizes the phenoxide ion and helps in maintaining acidity of the solution. When in an aqueous solution of pH between 8 and 12, a phenol dissociates and forms phenolate anion which has the chemical formula C6H5O-. This ion is also known as phenoxide. The phenoxide ion provides acidic character to the solution.

2. What are Some of the Uses of Phenol?

Phenol has several uses. It first found application as a disinfectant in surgical procedures. It is also well known as an old soap. Its cleansing abilities were often in use in this industry. With time, it shifted to household detergents and disinfectants. Apart from that, it finds application in several small-scale industries. It is present in industrial paint, and it removes a lot of resistant coating such as epoxy and polyurethane from parts manufactured in the aviation industry. It is also a part of a lot of drugs. Phenols also find a place in the making of sunscreens, exfoliators and other cosmetic products.