Naphthalene is a white crystalline compound used in mothballs and industrial processes. It emits a distinct odor and evaporates easily.
| IUPAC Name | Naphthalene |
| Molecular Formula | C10H8 |
| CAS Number | 91-20-3 |
| Synonyms | Tar Camphor, White Tar, Naphthalin, Albocarbon |
| InChI | InChI=1S/C10H8/c1-2-6-10-8-4-3-7-9(10)5-1/h1-8H |
Naphthalene Properties
Naphthalene Formula
The formula of naphthalene or naphthalin is C10H8. It consists of ten carbon atoms and eight hydrogen atoms. The formula represents the exact ratio of atoms present in a naphthalin molecule.
Naphthalene Molar Mass
The molar mass of naphthalin is 128.17 grams per mole. It is calculated by adding the atomic masses of all the atoms present in a naphthalin molecule.
Naphthalene Boiling Point
Naphthalin has a boiling point of approximately 218 degrees Celsius. This means that at temperatures above 218 degrees Celsius, naphthalin transforms from a solid to a gas phase.
Naphthalene Melting Point
The melting point of naphthalin is around 80 degrees Celsius. This indicates that naphthalin transitions from a solid to a liquid state when heated to temperatures above 80 degrees Celsius.
Naphthalene Density g/mL
Naphthalin has a density of about 1.145 grams per milliliter. Density is a measure of how much mass is contained in a given volume of a substance. In the case of naphthalin, it means that 1 milliliter of naphthalin weighs 1.145 grams.
Naphthalene Molecular Weight
The molecular weight of naphthalin is 128.17 grams per mole. It represents the average mass of a naphthalin molecule relative to the unified atomic mass unit (amu).
Naphthalene Structure
Naphthalin has a distinct structure consisting of two benzene rings fused together. The carbon atoms in each benzene ring are connected by a shared pair of carbon atoms, resulting in a fused ring system.
Naphthalene Solubility
Naphthalin is sparingly soluble in water, meaning it dissolves to a limited extent. However, it is highly soluble in organic solvents such as ethanol and benzene. This solubility behavior is due to differences in polarity between naphthalin and water.
| Appearance | White crystals |
| Specific Gravity | 1.145 g/mL |
| Color | Colorless |
| Odor | Distinct |
| Molar Mass | 128.17 g/mol |
| Density | 1.145 g/cm³ |
| Melting Point | 80°C |
| Boiling Point | 218°C |
| Flash Point | 79°C |
| Water Solubility | ~31.6 mg/L |
| Solubility | Soluble in organic solvents such as benzene, ethanol |
| Vapor Pressure | 0.4 mmHg at 25°C |
| Vapor Density | 4.37 (air = 1) |
| pKa | ~4.7 |
| pH | Neutral |
Naphthalene Safety and Hazards
Naphthalin poses safety hazards and should be handled with care. It is harmful if swallowed, inhaled, or absorbed through the skin. Avoid direct contact and wear appropriate protective gear when handling. It can irritate the eyes, skin, and respiratory system, causing discomfort. Keep it away from open flames as it is flammable and can release toxic fumes when burned. Store naphthalin in a well-ventilated area, away from incompatible substances. In case of exposure or ingestion, seek medical attention immediately. Always follow safety guidelines, use in a controlled environment, and store securely to minimize potential risks.
| Hazard Symbols | Harmful if swallowed, inhaled, or absorbed through the skin |
| Safety Description | Use with caution, wear protective gear, avoid direct contact |
| UN IDs | UN 1334 |
| HS Code | 2902.90.0000 |
| Hazard Class | 4.1 (Flammable solid) |
| Packing Group | III |
| Toxicity | Toxic to aquatic life with long-lasting effects |
Please note that the provided hazard symbols and safety description are representative, and it’s important to consult official sources and safety guidelines for specific and up-to-date information on naphthalin’s risk and safety precautions.
Naphthalene Synthesis Methods
Various methods enable the synthesis of naphthalin.
One common approach is the “dehydrogenation” of bicyclic compounds like decalin or tetralin at high temperatures, resulting in the formation of naphthalin. One method involves the catalytic reforming of petroleum fractions, yielding naphthalin as a byproduct.
Furthermore, “coal tar distillation” is an important industrial process for obtaining naphthalin. In this process, the collection of naphthalin-rich fractions occurs through fractional distillation of coal tar.
Moreover, the “decarboxylation” of phthalic acid or its derivatives can yield naphthalin. This reaction involves the removal of a carboxyl group to form the aromatic structure of naphthalin.
Additionally, the “alkylation” of benzene with alkyl halides followed by “cyclization” is a viable synthesis route to naphthalin. In this method, alkyl-substituted benzene compounds undergo a series of reactions to form the naphthalin ring system.
Each of these synthesis methods provides pathways to produce naphthalin, catering to various industrial requirements and applications. Researchers and industries employ these methods while considering factors like yield, efficiency, and safety for the successful production of naphthalin.
Naphthalene Uses
Naphthalin has various applications across different industries. Here are some key uses of naphthalin:
- Mothballs: Naphthalin in mothballs repels and prevents moth infestations in stored clothing and fabrics.
- Chemical Manufacturing: Naphthalin serves as a starting material in the production of various chemicals, including phthalic anhydride, used in manufacturing plastics.
- Dye Production: Naphthalin is vital in synthesizing dyes, particularly for producing vivid and bright colors in textiles and other materials.
- Solvent: Industries use naphthalin as a solvent for extracting organic compounds and formulating specialty chemicals, leveraging its low polarity.
- Insecticides: Naphthalin derivatives are instrumental in formulating insecticides and pesticides, effectively controlling pests and protecting crops.
- Concrete Additive: Naphthalin is an essential additive in concrete mixtures, acting as a water reducer and enhancing workability and flowability during construction.
- Fuel and Fuel Additives: Naphthalin serves as a fuel additive in gasoline and certain fuels due to its high energy content.
- Research and Laboratory Applications: Naphthalin finds application in scientific research, such as spectroscopy experiments and as a standard reference material.
The versatile properties of naphthalin make it a valuable compound across industries, contributing to areas ranging from pest control to chemical synthesis and beyond.
Questions:
Q: What is the boiling point of naphthalene?
A: The boiling point of naphthalin is approximately 218 degrees Celsius.
Q: How does naphthalene kill moths?
A: Naphthalin’s strong odor acts as a repellent, deterring moths from laying eggs and causing suffocation when inhaled by moths.
Q: What is the melting point of naphthalene?
A: The melting point of naphthalin is around 80 degrees Celsius.
Q: How toxic is naphthalene?
A: Naphthalin is toxic if ingested or inhaled, and it can cause irritation to the eyes, skin, and respiratory system.
Q: Where can I buy snow-white naphthalene balls?
A: Snow white naphthalin balls can be purchased at grocery stores, hardware stores, or online retailers.
Q: Can naphthalene balls kill humans?
A: Naphthalin balls can be harmful if ingested in large quantities, but they are not typically lethal to humans in small amounts.
Q: Is smelling naphthalene balls harmful?
A: Smelling naphthalin balls for a short time may cause irritation but is unlikely to cause serious harm.
Q: Is naphthalene soluble in water?
A: Naphthalin is sparingly soluble in water but highly soluble in organic solvents like benzene and ethanol.
Q: What are naphthalene balls?
A: Naphthalin balls are small white solid balls used to repel moths and protect stored clothes from infestation.
Q: In what order would you expect to find naphthalene?
A: Naphthalin is typically found in the gaseous phase when released into the environment.
Q: Is naphthalene polar?
A: No, naphthalin is nonpolar due to its symmetrical molecular structure.
Q: What is naphthalene?
A: Naphthalin is a white crystalline hydrocarbon compound with a distinctive odor, commonly used in mothballs and various industrial processes.
Q: What percentage of the naphthalene molecules emitted a photon?
A: It depends on the specific conditions, but a small percentage of naphthalin molecules can emit photons when excited by energy sources like UV light.