Nitrobenzene or C6H5NO2 is an organic compound with a pale-yellow color and a distinct odor. It is used as a precursor for the production of aniline and other chemicals. It is also a toxic substance.
| IUPAC Name | Nitrobenzene |
| Molecular Formula | C6H5NO2 |
| CAS Number | 98-95-3 |
| Synonyms | Nitrobenzol, Nitrobenzeen, Essence of Mirbane, NB |
| InChI | InChI=1S/C6H5NO2/c8-7(9)6-4-2-1-3-5-6/h1-5H |
Nitrobenzene Structure
Nitrobenzene has a flat and planar molecular structure. It consists of a benzene ring (C6H5) with a nitro group (-NO2) attached to one of the carbon atoms. The nitro group is an electron-withdrawing group, which means that it reduces the electron density of the benzene ring. This property makes nitrobenzene less reactive than benzene in many chemical reactions.
Nitrobenzene formula
The chemical formula of nitrobenzene is C6H5NO2. This formula represents the number and type of atoms that make up the molecule. The benzene ring provides the backbone of the molecule, while the nitro group provides a polar functional group that influences the properties of the compound. The formula of nitrobenzene is important in understanding its chemical and physical properties and its reactivity with other substances.
Nitrobenzene molar mass
The molar mass of nitrobenzene, also known as C6H5NO2, is 123.11 g/mol. This is calculated by adding up the atomic masses of all the atoms in the compound. Nitrobenzene has a relatively high molar mass, which is due to the presence of six carbon atoms and one nitrogen atom in its chemical structure.
Nitrobenzene boiling point
Nitrobenzene has a boiling point of 210.9 °C. This is relatively high compared to other organic compounds with similar molecular weights. The high boiling point is due to the presence of strong intermolecular forces of attraction between the nitrobenzene molecules, such as hydrogen bonding and dipole-dipole interactions.
Nitrobenzene melting point
The melting point of nitrobenzene is 5.85 °C. This is relatively low compared to its boiling point, which can be explained by the fact that the intermolecular forces of attraction in the solid state are weaker than in the liquid state. Additionally, nitrobenzene can exhibit polymorphism, meaning it can exist in multiple crystal structures with different melting points.
Nitrobenzene density g/ml
The density of nitrobenzene is 1.20 g/mL at room temperature (25 °C). This means that nitrobenzene is denser than water, which has a density of 1 g/mL at the same temperature. The density of nitrobenzene is influenced by its molecular weight and the size and shape of its molecules.
Nitrobenzene molecular weight
The molecular weight of nitrobenzene is 123.11 g/mol. This is calculated by adding up the atomic masses of all the atoms in the compound. The molecular weight of nitrobenzene is important in determining its physical and chemical properties, such as boiling point, melting point, and solubility.
| Appearance | Pale yellow liquid |
| Specific Gravity | 1.20 g/cm3 |
| Color | Pale yellow |
| Odor | Characteristic |
| Molar Mass | 123.11 g/mol |
| Density | 1.20 g/mL at 25 °C |
| Melting Point | 5.85 °C |
| Boiling Point | 210.9 °C |
| Flash Point | 77 °C |
| Water Solubility | 7.9 g/L at 25 °C |
| Solubility | Soluble in organic solvents |
| Vapour Pressure | 0.68 mmHg at 25 °C |
| Vapour Density | 4.35 (air=1) |
| pKa | -1.15 |
| pH | 7 (neutral) |
Nitrobenzene Safety and Hazards
Nitrobenzene is a highly toxic substance that poses several safety and health hazards. It can cause irritation to the skin, eyes, and respiratory tract upon contact or inhalation. Prolonged exposure to nitrobenzene can cause liver and kidney damage, anemia, and methemoglobinemia. Nitrobenzene is also highly flammable and can ignite at relatively low temperatures. Additionally, it can release toxic fumes when heated, burned, or decomposed. Therefore, it is essential to handle nitrobenzene with care, wear appropriate protective equipment, and store it in a cool and dry place away from ignition sources and incompatible substances.
| Hazard Symbols | T, N |
| Safety Description | Highly toxic, harmful if swallowed, inhaled, or absorbed through the skin, causes severe skin burns and eye damage |
| UN Ids | UN1662 |
| HS Code | 2904.90.90 |
| Hazard Class | 6.1 |
| Packing Group | II |
| Toxicity | Highly toxic |
Nitrobenzene Synthesis Methods
Nitrobenzene can be synthesized by several methods, including the nitration of benzene, the reduction of nitrobenzene, and the hydrogenation of nitrobenzene. The most commonly used method is the nitration of benzene, which involves the reaction of benzene with a mixture of nitric acid and sulfuric acid at a temperature of around 50°C. The nitration reaction produces a mixture of nitrobenzene, along with other nitro derivatives of benzene.
Another method for synthesizing nitrobenzene is the reduction of nitrobenzene, which involves the use of reducing agents such as iron or zinc and hydrochloric acid. The reduction reaction converts the nitro group (-NO2) of nitrobenzene to an amino group (-NH2), producing aniline as a byproduct.
The hydrogenation of nitrobenzene is another method for synthesizing aniline. This method involves the use of a catalyst, such as nickel or palladium, and hydrogen gas, which reacts with nitrobenzene to produce aniline.
Nitrobenzene Uses
Nitrobenzene is a versatile chemical that is used in a wide range of applications.
- The chemical industry uses nitrobenzene as a precursor to aniline, which is an important ingredient in the production of dyes, rubber, and pharmaceuticals. Nitrobenzene is a valuable feedstock for the manufacture of other chemicals like phenol, which is used in the production of plastics, resins, and adhesives.
- Organic compounds such as oils, fats, and waxes can be dissolved using nitrobenzene, which makes it a useful solvent. In the food industry, nitrobenzene is used as a flavoring agent, primarily in chewing gum production.
- C6H5NO2 is an essential component in the production of explosives like TNT (trinitrotoluene). As a fuel additive, nitrobenzene helps increase the octane rating of gasoline.
- C6H5NO2 is also an ingredient in the manufacture of various pesticides and herbicides, including insecticides and fungicides.
- The production of synthetic fibers like nylon also relies on nitrobenzene as a vital component.
Overall, the versatile nature of nitrobenzene makes it an essential chemical in many industries, including the chemical, food, and textile industries. However, proper handling and safety precautions are necessary when using nitrobenzene due to its toxicity and flammability.
Questions:
Nitrobenzene to aniline reaction
The conversion of nitrobenzene to aniline is a two-step reaction that involves the reduction of the nitro group (-NO2) to an amino group (-NH2) and subsequent hydrolysis of the intermediate product.
The reduction of C6H5NO2 is typically carried out using a reducing agent, such as iron or zinc, and an acidic solution, such as hydrochloric acid. The reaction produces an intermediate product, nitrosobenzene, which is further reduced to aniline in the presence of an acid or base catalyst.
The hydrolysis of the intermediate nitrosobenzene to aniline is carried out by treating the intermediate with an acidic solution, such as dilute hydrochloric acid. The reaction produces aniline, along with water and nitrogen oxide (NO).
The overall reaction can be represented as: Nitrobenzene + 3 H2 → Aniline + 2 H2O + N2