An organic acid with the chemical formula C3H6O3 is Lactic acid which is also known as Milk acid. It also happens to be an alpha-hydroxyl acid because of the presence of the carboxyl group adjacent to the hydroxyl group.
When milk sugar (lactose) undergoes fermentation then the product obtained is lactic acid. Lactic acid is found in cottage cheese, laban, sour milk, yogurt, and Koumiss. There are two forms of optical isomers of lactic acid Levo and Dextro. In 1780, Swedish chemist Carl Wilhelm Scheele, isolated lactic acid from sour milk for the first time.
Lactic acid is water-soluble and white in its solid state whereas it is colourless in its liquid state. lactic acid soluble salt like calcium lactate can be used as a source of calcium.
L-isomers are commonly present among living organisms. Lactic acid plays an important part in various biochemical processes. It is also produced by the muscles during intense activity. It is a chemical byproduct of anaerobic respiration. It gets produced in yogurt by some bacteria and is also present in your gut and blood.
Properties of Lactic Acid
Physical properties of Lactic Acid
| Chemical Formula of Lactic Acid | C3H6O3 |
| Molar Mass/Molecular Weight | 90.08 g/mol |
| Extended Formula of Lactic Acid | CH3CH(OH)CO2H |
| Boiling Point of Lactic Acid | 122°C |
| Melting Point of Lactic Acid | 16.8°C |
| PH of Lactic Acid | 3.51 |
| Colour of Lactic Acid | White in solid-state. Colourless in the liquid state |
| Solubility of Lactic Acid | Soluble in water |
Chemical properties of Lactic Acid
- It happens to be a weak organic acid. Furthermore, It can react with other stronger acids.
- There is an important characteristic of lactic acid is the double physical state.
- This double physical state includes the liquid state of the racemic mixture of D, L-lactic acid and solid white powder state of the enantiopure.
Structure of Lactic Acid
An organic acid with chemical formula C3H6O3 is Lactic acid which is also known as Milk acid. It also happens to be an alpha-hydroxyl acid because of the presence of the carboxyl group adjacent to the hydroxyl group.
Preparation of Lactic Acid
Lactic Acid can be prepared from two strategies:
First the biotechnological method: In this method, the large scale production of this acid takes place by the fermentation of carbohydrates and nutrients. This fermentation is only possible due to the microorganism of the genus Lactobacillus. This fermentation also results in the production of formic and acetic acid.
Second synthetic method: In this method, The synthetic preparation of lactic acid takes place from carbon monoxide and acetaldehyde in acid solution. This takes place at a temperature of 130-200ºC.
Uses Of Lactic Acid
- Lactic acid is used in medicine as an intravenous fluid that acts as an isotonic to resuscitate after blood loss.
- Lactic acid works as a raw material to produce various polymers.
- Lactic acid has wide usage in the food industry because this acid is a good food preservative and flavouring agent.
- Lactic acid is important in the manufacture of detergent and mosquitoes lure in the chemical industry.
- Lactic acid can get formed using a synthetic process or fermentation. later on involves the usage of nutrients like amino acids, vitamins, peptides, glucose, and salt. All these nutrients get combined with microbes, which further uses nutrients to give out lactic acid.
- Lactate plays an important role in the healing of traumatic brain injuries. The release of norepinephrine in the brain is signalled by lactate.
- For Personal products and healthcare products.
- It acts as a Food preservative.
- It is used for Paint and coating additives and also used in Furniture care products.
- It is also used in Textile dyeing and leather tanning.
- Lactic acid helps in the coagulation of protein in milk.
Sample Questions
Question 1: What is the Formula and IUPAC name of Lactic acid?
Answer:
The chemical formula C3H6O3. Its IUPAC name is 2-Hydroxypropanoic acid
Question 2: What is the effect of lactic acid on the body?
Answer:
In body, when oxygen level is low it requires the conversion glucose into energy, it makes lactic acid. This production of lactic acid can cause muscle pain, cramps and muscle fatigue. These type of symptoms are normal during physical exercise. After doing lots of physical activities or exercises, we often feel tired, fatigue, or even muscle cramps in our bodies. It is because of the accumulation of lactic acid in muscles, and When it reacts with extra oxygen that we inhale, breaking it into carbon dioxide and water. This lead to the break down of lactic acid as we get relief in cramps or muscle pain .
Question 3: Which food holds the lactic acid?
Answer:
Lactic acid is present in sour dairy products, such as yogurt, koumiss, kefir, laban, and some cottage cheese. When milk sugar (lactose) undergoes fermentation then the product obtained is lactic acid
Question 4: What is the melting and boiling point of Lactic Acid?
Answer:
Boiling Point of Lactic Acid: 122°C
Melting Point of Lactic Acid: 16.8°C