Resorcinol Formula – Structure, Properties, Uses, Sample Questions

Resorcinol compound consists of elements Carbon, Hydrogen, and Oxygen. Carbon is a nonmetal present in group-14 of the periodic table. Its atomic number is 6 and is represented with the symbol C. Hydrogen is a colorless, odorless, tasteless, and flammable gas. Its atomic number is 1 and is represented with the symbol H. Oxygen is a highly reactive nonmetal and a good oxidizing agent. It is present in the chalcogen group of the periodic table. Its atomic number is 8 and is represented by the symbol O.

Resorcinol Formula 

Resorcinol is a white crystalline solid organic compound with a faint odor and sweetish to bitter taste. Its chemical formula is C₆H₆O₂. It is soluble in water, alcohol, and ether, but it doesn’t dissolve Chloroform and Carbon disulfide. It is difficult to ignite. C₆H₆O₂ is one of the three isomeric benzenediols. It is a 1,3-isomer of benzenediol, i.e., benzene dihydroxylated at 1 and 3 positions. The other names of Resorcinol are Resorcin, 3-Hydroxyphenol, m-Benzenediol, and m-Dihydroxybenzene. Resorcin doesn’t occur naturally in a free state but is found in argan oil. It turns into pink color on exposure to air and light.

Preparation of Resorcinol

Resorcinol crystallizes from benzene as colorless needles. Resorcinol is prepared by a classic sulfonate fusion process. Firstly benzene is treated with sulfuric acid at 100°C, which gives mono sulfonic acid. It is converted into m-disulfonic acid with 65% oleum at 85°C. Now m-Benzenedisulfonate melts in Sodium Hydroxide(NaOH) at 300 °C to give Resorcinol and Sodium sulfite. 

Structure of Resorcinol

Resorcinol structure

Physical Properties of Resorcinol

• Resorcinol appears in white solid form.
• Odor of Resorcinol is a faint Benzene odor.
• The molecular weight of Resorcinol is 110.1 g/mol.
• The melting point of Resorcinol is 110°C.
• Its boiling point is 277°C.
• The density of Resorcinol is 1.28 g/cm³.

Chemical Properties of Resorcinol

• Resorcinol (C₆H₆O₂) on partial hydrogenation gives Dihydroresorcinol (C₆H₈O₂), which is also known as 1,3-cyclohexanedione.
• Sodium amalgam (NaHg) reduces Resorcinol (C₆H₆O₂) to dihydro resorcinol (C₆H₈O₂). The resultant is heated to 150 to 160 °C with a concentrated barium hydroxide solution to give γ-acetylbutyric acid (C₆H₁₀O₃).
• Resorcinol reduces Fehling’s solution and ammoniacal silver solutions.

Uses of Resorcinol

• Resorcinol is used as a sensitizer and an erythropoietin inhibitor.
• It is used in the production of resins.
• Resorcinol is widely used in the making plastics and pharmaceuticals.
• It is used as an intermediate in the synthesis of organic compounds.
• Resorcinol is used in the treatment of acne.
• It is a disinfectant and analytical reagent.

Sample Questions

Question 1: What happens when Resorcinol reacts with Sodium nitrite?

Answer:

Resorcinol reacts with sodium nitrite to forms a water soluble blue dye called lacmoid, which is turned red by acids. It is used as a pH indicator.

Question 2: Find the molecular weight of Resorcinol?

Answer:

Resorcinol consists of 6 Carbons, 6 Hydrogens and 2 Oxygen atoms.

Atomic weight of each Carbon = 12.01 

Atomic weight of each Hydrogen = 1.00784 

Atomic weight of each Oxygen = 15.999 

Molar mass of C₆H₆O₂ = (6 × 12.01) + (6 × 1.00784) + (2 × 15.999)

= 110.1 g/mol

Question 3: Give any additional way to prepare Resorcinol?

Answer:

There are many additional ways to prepare resorcinol. Resorcinol was formerly produced by disulfonation of benzene followed by hydrolysis of the 1,3-disulfonate. This method has been discarded because it generate so much sulfur containing waste along with Resorcinol. 

Question 4: Is Resorcinol hazardous to health?

Answer:

Yes, resorcinol is hazardous to health. Repeated exposure can affect the nervous system. Exposure to very high levels of Resorcinol may cause breathing problems, collapse and even death. 

Question 5: What are the uses of Resorcinol?

Answer: 

Resorcinol is used to treat several problems related to skin. It has an ability to break down rough, hardened, scaly skin. It is also used in production of plastics, resins and pharmaceuticals.

Question 6: What compound is yielded when Resorcinol reacts with nitric acid in the presence of sulfuric acid?

Answer:

Resorcinol (C₆H₆O₂) reacts with nitric acid (HNO₃) in presence of sulfuric acid to yield Trinitroresorcinol (C₆H₃N₃O₈) which is an explosive compound.