N-Ethylbenzene sulphonamide is an organic compound known for its alkali solubility and chemical stability. This property makes it valuable in industrial applications, pharmaceuticals, and chemical synthesis.
In this topic, we will explore why N-ethylbenzene sulphonamide is soluble in alkali, its molecular structure, properties, and industrial uses.
Understanding N-Ethylbenzene Sulphonamide
1. What is N-Ethylbenzene Sulphonamide?
N-Ethylbenzene sulphonamide is a derivative of benzene sulphonamide, where an ethyl group (-C₂H₅) is attached to the nitrogen atom. It belongs to the sulphonamide family, which is widely used in chemical and pharmaceutical industries.
2. Molecular Structure
The molecular structure consists of:
- A benzene ring (aromatic stability)
- A sulphonamide (-SO₂NH) functional group
- An ethyl (-C₂H₅) group attached to nitrogen
3. Chemical Formula and Properties
| Property | Description |
|---|---|
| Chemical Formula | C₈H₁₁NO₂S |
| Molecular Weight | ~185 g/mol |
| Appearance | White to off-white crystalline solid |
| Solubility | Soluble in alkali, slightly soluble in water |
| Stability | Stable under normal conditions |
Why is N-Ethylbenzene Sulphonamide Soluble in Alkali?
1. Role of the Sulphonamide Group (-SO₂NH₂)
The sulphonamide group contains a hydrogen atom attached to nitrogen, making it slightly acidic. This means it can react with alkali (such as NaOH or KOH) to form a water-soluble salt.
2. Acid-Base Interaction
- When N-ethylbenzene sulphonamide is mixed with an alkali solution, the proton (H⁺) from the sulphonamide group is removed.
- This results in the formation of a negatively charged sulphonamide ion, which dissolves in water due to increased polarity.
3. Formation of Water-Soluble Salts
The reaction with alkali leads to the formation of a sodium or potassium salt, which is highly soluble in water.
Example reaction:
C₈H₁₁NO₂S + NaOH → C₈H₁₀NO₂S⁻ Na⁺ + H₂O
This reaction enhances the solubility of N-ethylbenzene sulphonamide in alkaline solutions.
Comparison: Solubility in Alkali vs. Water
| Solvent | Solubility | Reason |
|---|---|---|
| Water | Slightly Soluble | Weak hydrogen bonding |
| Alkali Solution | Highly Soluble | Forms water-soluble ionic salts |
Since water does not ionize the sulphonamide group effectively, its solubility remains low. However, in alkali solutions, ionization occurs, leading to increased solubility.
Industrial and Pharmaceutical Applications
1. Use in Chemical Synthesis
N-Ethylbenzene sulphonamide is a key intermediate in producing various chemicals, including dyes, plasticizers, and surfactants.
2. Pharmaceutical Importance
- Sulphonamides are widely used in antibacterial drugs.
- N-Ethylbenzene sulphonamide derivatives are investigated for therapeutic applications.
3. Polymer and Plastic Industry
- Acts as a plasticizer to improve flexibility and durability.
- Used in resins, coatings, and adhesives.
4. Role in Agrochemicals
- Some sulphonamide derivatives are used in pesticides and herbicides.
- Enhances the effectiveness and solubility of active ingredients.
Reactivity with Other Compounds
1. Reaction with Strong Acids
N-Ethylbenzene sulphonamide does not dissolve well in acidic solutions because the sulphonamide group remains protonated, reducing polarity.
2. Stability Under Heat and Pressure
- Resistant to decomposition under normal conditions.
- Can be used in high-temperature applications.
3. Interaction with Organic Solvents
- Soluble in some organic solvents like alcohols and acetone.
- Shows limited solubility in non-polar solvents like benzene and toluene.
Environmental and Safety Considerations
1. Biodegradability and Toxicity
- Sulphonamide compounds can persist in the environment, requiring proper disposal.
- Some derivatives are bioaccumulative, meaning they can stay in biological systems.
2. Handling and Storage
- Should be stored in a dry, cool place.
- Avoid contact with strong acids and oxidizing agents.
3. Waste Management
- Dispose of according to chemical waste regulations.
- Dilute alkaline solutions before disposal to reduce environmental impact.
Frequently Asked Questions (FAQs)
1. Why does N-Ethylbenzene sulphonamide dissolve in alkali but not in water?
In alkali, it forms a water-soluble ionic salt, increasing solubility. In water, there is no ionization, so it remains mostly insoluble.
2. What happens when N-Ethylbenzene sulphonamide is mixed with a strong acid?
It remains undissolved because the sulphonamide group does not ionize in acidic conditions.
3. What are the common uses of N-Ethylbenzene sulphonamide?
It is used in chemical synthesis, pharmaceuticals, plastics, and agrochemicals.
4. Is N-Ethylbenzene sulphonamide hazardous?
While it is generally stable, it should be handled with care to avoid environmental contamination.
5. Can N-Ethylbenzene sulphonamide be used in drug formulations?
Some sulphonamide derivatives are used in medicine, but this specific compound is mainly used in industrial applications.
N-Ethylbenzene sulphonamide is an alkali-soluble compound due to the ionization of its sulphonamide group in basic solutions. This property makes it valuable in chemical, pharmaceutical, and industrial applications.
Understanding its solubility, reactivity, and applications helps in optimizing its use in various industries while ensuring safe handling and environmental protection.