Butyric Acid: Overview, Questions, Preparation

Butyric is a colourless short-chain fatty acid found in plant oils and animal fats in the form of esters. The chemical formula of Butyric acid is CH3CH2CH3-COOH or C4H8O2. Butyric acid finds its importance in many industries as raw materials.

Butyric acid is also found in human bodies in the form of fatty acid when a good bacteria in your gut breaks the dietary fibres.

3D model of Butyric Acid

Chemical structure of Butyric Acid

Let us look at some of the physical properties of Butyric acid:

1. The molecular weight of Butyric acid is 88.106 g/mol.
2. The density of Butyric acid is 1.135 g/cm3.
3. The freezing point of Butyric acid is -7.9 oC or 17.8 oF and the boiling point is 163.5 oC or 326.3 oF.
4. The refractive index of Butyric acid is 1.3980.
5. The pH level of Butyric acid is 4.82.
6. Butyric acid is soluble in ether and ethanol and slightly soluble in Carbon tetrachloride (CCl4).
7. Butyric acid is a colourless fatty acid and gives a foul odour.
8. Butyric acid can be detected by dogs up to ten ppb. Humans can also detect Butyric acid if it is found above 10ppm.

Now, let us look at some of the chemical properties of Butyric acid:

1. When Butyric acid is chemically reacted with water, it produces acetic acid and ether. 
2. When Butyric acid is chemically reacted with sodium hydroxide, we get a sodium salt of Butyric acid alongside water. The sodium salt of Butyric acid is used in various forms. 

1. The esters with low molecular weight produce a pleasant smell and find its use in the perfume industry. It is even used as a food flavouring agent in some countries.
2. Butyric acid produces various types of esters, one of which is cellulose acetate butyrate. It is used in preparing paints, coatings, varnishes and various tools. But proper care has to be taken to not bring these products in contact with moisture, or it may release Butyric acid from it, and the product would be deemed not usable.
3. Because of the odour produced by various esters manufactured from Butyric acid, it is used as one component in the fishing baits mixture.
4. Butyric acid finds its commercial use in the beer industry.
5. Butyric acid is used in the production of caramel, cheese, soda water syrups, and butter.
6. Butyric acid has its uses in the manufacture of cosmetics.

Butyric Acid and its other compounds are explained in the chapter ‘Acids, Bases and Salts’ along with their properties, reactions, testing and various other features.

There is a mention about Butyric acid in the chapter ‘Aldehydes, Ketones and Carboxyl group’ in the nomenclature part. You can find their chemical formula and structure in it.

1. 10 mL of NaOH is found to be completely neutralised by 8 ml of HCl. If we take 20 ml of NaOH, what would be the amount of HCl required to neutralise it?

(a) 8 ml (b) 16 ml (c)  4ml (d) 12 ml

Answer: (b)

2. Equal lengths of Magnesium ribbons are taken in tube A, and B. Hydrochloric acid (HCl) is added to tube A, and acetic acid (CH3COOH) is added to tube B. The amount and concentration on both the tubes are equal. In which test tube, would you find more fizzing and why?

Answer: Test Tube A because when Magnesium reacts with an acid, it gives away Hydrogen and HCl is a stronger acid than acetic acid. So, tube A would liberate more Hydrogen, which would cause more vigorous fizzing.

3. Fresh milk has a pH of 6. How do you think the pH will change as it turns into curd? Explain.

Answer: When milk changes into curd, the pH decreases as curd contains lactic acid. Acids have a pH value of less than 7.

Q: What is the chemical formula of Butyric Acid?

Q: How does Butyric Acid physically look?

Q: What is the freezing and boiling point of Butyric Acid?

Q: What is the pH level of Butyric Acid?

Q: Where does Butyric Acid find its use commercially?