Benzaldehyde is a colorless liquid with a pleasant almond-like odor. It is used in the production of dyes, perfumes, and flavors.
| IUPAC Name | Benzaldehyde |
| Molecular Formula | C7H6O |
| CAS Number | 100-52-7 |
| Synonyms | Benzenecarbaldehyde, Phenylmethanal, Benzoic aldehyde, Benzenecarbonal |
| InChI | InChI=1S/C7H6O/c8-6-7-4-2-1-3-5-7/h1-6H |
Benzaldehyde Properties
Benzaldehyde Formula
The formula of benzoic aldehyde is C7H6O. It consists of seven carbon atoms, six hydrogen atoms, and one oxygen atom. The arrangement of these atoms forms the molecular structure of benzoic aldehyde.
Benzaldehyde Molar Mass
The molar mass of benzoic aldehyde is calculated by adding the atomic masses of all its constituent atoms. Benzaldehyde has a molar mass of approximately 106.12 grams per mole. This value is important for various calculations and chemical reactions involving benzoic aldehyde.
Benzaldehyde Boiling Point
Benzoic aldehyde has a boiling point of around 179-180 degrees Celsius. At this temperature, benzoic aldehyde undergoes a phase change from a liquid to a gas. The boiling point is influenced by intermolecular forces and molecular structure.
Benzaldehyde Melting Point
The melting point of benzoic aldehyde is approximately -26 degrees Celsius. It signifies the temperature at which benzoic aldehyde transitions from a solid to a liquid state. The melting point is affected by factors such as molecular interactions and crystal lattice structure.
Benzaldehyde Density g/mL
Benzoic aldehyde exhibits a density of about 1.045 grams per milliliter (g/mL). Density represents the mass per unit volume of a substance. Benzoic aldehyde’s density is determined by the arrangement and packing of its molecules within a given volume.
Benzaldehyde Molecular Weight
The molecular weight of benzoic aldehyde is approximately 106.12 grams per mole. It is calculated by summing the atomic weights of all the atoms present in one molecule of benzoic aldehyde. Molecular weight is useful for various stoichiometric and quantitative analyses.
Benzaldehyde Structure
The structure of benzoic aldehyde consists of a benzene ring (a hexagonal ring of carbon atoms) with a formyl group (-CHO) attached to it. This formyl group is responsible for the aldehyde functional group in benzoic aldehyde. The structure determines its reactivity and properties.
Benzaldehyde Solubility
Benzoic aldehyde is sparingly soluble in water but dissolves readily in organic solvents such as ethanol, ether, and chloroform. Its solubility depends on the polarity and intermolecular interactions between benzoic aldehyde molecules and the solvent molecules.
| Appearance | Colorless liquid |
| Specific Gravity | 1.044-1.049 g/mL |
| Color | Colorless |
| Odor | Pleasant almond-like |
| Molar Mass | 106.12 g/mol |
| Density | 1.045 g/mL |
| Melting Point | -26 °C |
| Boiling Point | 179-180 °C |
| Flash Point | 63 °C |
| Water Solubility | Slightly soluble |
| Solubility | Soluble in organic solvents such as ethanol, ether, and chloroform |
| Vapour Pressure | 2.67 mmHg at 25 °C |
| Vapour Density | 3.7 (air = 1) |
| pKa | 14.19 |
| pH | Approximately 6-7 |
Benzaldehyde Safety and Hazards
Benzoic aldehyde poses certain safety hazards that need to be considered. It is flammable and can ignite if exposed to an open flame or heat source. Care should be taken to store and handle it away from ignition sources. When handling benzoic aldehyde, it is important to wear appropriate personal protective equipment, such as gloves and goggles, to prevent contact with skin and eyes. It may also cause respiratory irritation if inhaled, so proper ventilation is necessary. In case of accidental ingestion or exposure, immediate medical attention should be sought. Overall, practicing good safety measures and following proper handling protocols is crucial to ensure the safe usage of benzoic aldehyde.
| Hazard Symbols | Flammable, Irritant |
| Safety Description | Highly flammable liquid. Harmful if swallowed or inhaled. |
| UN IDs | UN 1990 |
| HS Code | 2912.19.00 |
| Hazard Class | 3 (Flammable liquids) |
| Packing Group | III |
| Toxicity | Benzaldehyde is considered to have low acute toxicity. It may cause irritation to the respiratory system and skin. Proper handling and ventilation are important. |
Benzaldehyde Synthesis Methods
Several methods enable the synthesis of benzoic aldehyde. One widely used approach involves oxidizing toluene using oxidizing agents like potassium permanganate or chromic acid. Controlled conditions introduce the oxidizing agent, converting toluene into benzoic aldehyde.
Another method entails oxidizing benzyl alcohol using suitable agents such as potassium dichromate or sodium dichromate, which transforms benzyl alcohol into benzoic aldehyde.
The benzoic aldehyde can also derive from benzyl chloride through treatment with an alkaline solution like sodium hydroxide. This process, known as the Cannizzaro reaction, produces benzoic aldehyde and sodium benzoate.
The Perkin reaction serves as another important means of synthesizing benzoic aldehyde. It involves the condensation of benzoic aldehyde with acetic anhydride in the presence of an alkali catalyst, yielding cinnamic acid. Further oxidation can convert cinnamic acid back into benzoic aldehyde.
Chemists can extract benzoic aldehyde from natural sources. It naturally occurs in various essential oils, such as bitter almond oil. One can obtain benzoic aldehyde by distilling or extracting these oils using solvents.
These diverse synthesis methods offer alternative pathways for commercially manufacturing benzoic aldehyde to fulfill various industrial requirements.
Benzaldehyde Uses
Benzoic aldehyde finds numerous applications in various industries due to its versatile properties. Here are some key uses of benzoic aldehyde:
- Flavor and Fragrance Industry: The flavor and fragrance industry widely uses benzoic aldehyde as a flavoring agent and fragrance ingredient. It enhances the aroma of almond, cherry, and other fruit-flavored foods, beverages, and confectioneries.
- Pharmaceutical Industry: The pharmaceutical industry utilizes benzoic aldehyde as a building block in synthesizing pharmaceutical compounds. It plays a crucial role in producing various drugs, including antibiotics, antipsychotics, and anti-inflammatory medications.
- Chemical Intermediates: Benzoic aldehyde acts as an intermediate in synthesizing various chemicals. It serves as a precursor in manufacturing dyes, rubber additives, plasticizers, and agrochemicals.
- Perfume Industry: The perfume industry extensively incorporates benzoic aldehyde into perfumes and cosmetic products. Its pleasant aroma adds a distinctive note to perfumes, soaps, lotions, and other personal care items.
- Food Industry: The food industry uses benzoic aldehyde as a flavor enhancer in baked goods, candies, and beverages. It imparts a characteristic almond-like taste, enhancing the overall flavor profile.
- Laboratory Reagent: Benzoic aldehyde serves as a reagent in various laboratory experiments and organic synthesis reactions.
- Photographic Industry: The photographic industry utilizes benzoic aldehyde as a chemical intermediate and solvent in photographic processing.
- Pesticide Industry: The pesticide industry relies on benzoic aldehyde as a key component in producing pesticides and insecticides used in agriculture to control pests and diseases.
The diverse applications of benzoic aldehyde highlight its significance across different sectors, making it a valuable compound in numerous industries.
Questions:
Q: Is benzaldehyde soluble in water?
A: Benzoic aldehyde is slightly soluble in water.
Q: What was the overall yield of making trans-cinnamic acid starting with benzaldehyde (2 steps)?
A: The overall yield depends on the specific reaction conditions and methods employed.
Q: Why can’t benzaldehyde react with itself by the aldol dehydration reaction?
A: Benzoic aldehyde lacks alpha hydrogen necessary for the aldol dehydration reaction to occur.
Q: Is benzaldehyde or acetophenone more polar?
A: Benzoic aldehyde is more polar than acetophenone.
Q: Is benzaldehyde polar?
A: Yes, the benzoic aldehyde is a polar compound.
Q: Does benzaldehyde give the Fehling test?
A: No, benzoic aldehyde does not react with Fehling’s reagent.
Q: How to convert benzoic acid to benzaldehyde?
A: Benzoic acid can be converted to benzoic aldehyde by decarboxylation using heat and a suitable catalyst.
Q: How to convert benzaldehyde to benzyl alcohol?
A: Benzoic aldehyde can be converted to benzyl alcohol through reduction using reducing agents such as sodium borohydride.
Q: Does benzaldehyde have alpha hydrogen?
A: No, benzoic aldehyde does not have an alpha hydrogen.
Q: What is the density of benzaldehyde?
A: The density of benzoic aldehyde is approximately 1.045 g/mL.
Q: What is benzaldehyde?
A: Benzoic aldehyde is an organic compound with a pleasant almond-like odor.
Q: What is benzaldehyde used for?
A: Benzoic aldehyde is used in various industries, including flavors, fragrances, pharmaceuticals, and chemical synthesis.
Q: Is benzaldehyde dangerous?
A: Benzoic aldehyde can be hazardous if mishandled or inhaled in large quantities. Proper safety precautions should be followed during handling and usage.