What is Acetic Acid?
Acetic acid is a important member of carboxylic acid group. Name assigned to acetic acid is ethanoic acid by IUPAC. CH3COOH is the formula of ethonic/acetic acid. It has a pungent odour and is colourless. Molecular mass is 60.052 g/mol. Density of acetic acid is 1.04g/cm³.
Production of acetic acid is done by process of fermentation of ethyl alcohol. The alcohol is oxidised by the oxygen in the air by bacterial action and acetic acid is produced. In industries production of acetic acid is done by catalyst oxidation of acetaldehyde. Acetic acid belong to group of weak acid. So process of electrolysis does not take place. It is found in nature also in plants.
Acetic acid is used in various ways. At home, it is used in the preparation of food. It is also added to pickles as a preservative. It is also used in cooking and cleaning purpose. The best-known form of acetic acid is vinegar. Vinegar is basically acetic acid with a large quantity of water i.e very diluted form of acetic acid.
What is Glacial Acetic Acid?
Glacial acid is very concentrated with minimum dilution. Water content in this is very less. It has a special property to freeze below temperature of 16°C . Because of this freezing property it is called glacial acetic acid. It is a liquid which is colourless and very corrosive in nature. Because of its corrosive nature glacial acetic acid needs extra care while handling, as it can cause injuries to skin. Density of glacial acetic acid is 1.05g/cm³.
Glacial acetic acid is laboratory prepared acid. It is formed by dipping solution of acetic acid over a stalactite of glacial acetic acid. It has property of forming crystals. Below a certain temperature glacial acetic acid freezes.
Glacial acetic acid cannot be consumed directly as it is highly corrosive. Crystals of glacial acetic acid is used for purifying water. It is also used as polar-base solvent and in manufacture of Aniline, Terephthalic acid etc. Glacial acetic acid is also used for production of esters.
One should always take certain precaution to avoid any mishap while using glacial acetic acid. Some of the precautions are:
• Always wear a lab coat- Lab coat protects the skin and clothes from any damage, in case acid gets splashed. It acts as a barrier between acid and the person.
• Gloves and safety spectacles- Wearing gloves insure the safety of hand. Safety spectacles prevents any irritation or burning sensation in eyes.
• Diluting acid- While diluting an acid one should always remember to add acid into water and not water into acid. This is the most common mistake made and hence should be strictly avoided. When water is added to acid the temperature of acid and container start rising. The heat produced is so much that the container may break and acid inside get splashed.
Difference Between Acetic Acid and Glacial Acetic Acid
- Acetic acid is an extensively diluted form of pure acid. While glacial acetic acid is without any dilution.
- Acetic acid do not freeze. While glacial acetic acid freezes below 16°C.
- Acetic acid do not form crystals. While glacial acid forms crystals.
- Acetic acid is mildly acidic because of it’s high water content. On the other hand, glacial acetic acid is highly corrosive.
- Acetic acid is used in the preparation of food. But glacial acetic acid cannot be used for this purpose as it is highly corrosive.
Comparison Between Acetic Acid and Glacial Acetic Acid
| Parameters | Acetic acid | Glacial acetic acid |
| Meaning | It is solution of acid and water | It is concentrated form of acid which freezes below 16°C |
| Concentration | Diluted form i.e contains large quantity of water | Concentrated form i.e contains very less amount of water |
| Formation of crystals | Cannot form crystal | Can form crystals |
| Preparation | Air oxidation of acetaldehyde | Dipping acetic acid on a frozen form of acetic acid |
| Freezing point | Cannot freeze | Freezes below 16°C |
| Uses | Used as a food preservative | Used for recrystallization |