Why is benzoic acid soluble in water and its uses

Why is benzoic acid soluble in water is a question asked in the field of Chemistry. Benzoic acid is a compound found in trace amounts, mostly as benzoic derivatives and esters, in many plants, fruits and other natural sources. It is widely used as a food additive to impart a pleasant "tart" or "sweet" taste to foods such as jams and jellies, soft drinks, candies, ice creams; it also occurs naturally in some animal tissues such as milk cheese. Benzoic acid occurs among low molecular weight compounds present on the surface of all proteins when proteins are denatured by heat or proteases during cooking (aged meat). In humans only 0.Benzoic acid is soluble in water due to the following;

1. It is highly polar

Polar at room temperature. Therefore it attracts water molecules and makes it soluble in water. This polarity is due to the presence of hydroxyl (OH) group on one end and carbonyl group (C=O) on the other end. The OH group is more electronegative than the carbonyl group because of which electrons from water molecules get transferred from water to OH side and from C=O to H side. As a result the hydrogen bonds are formed between benzoic acid and water molecules. This explains why is benzoic acid soluble in water.

2. It has high boiling point

Benzoic acids have boiling point above 100 degree Celsius, thus it does not evaporate at room temperature when in contact with water. It is less volatile and will not evaporate by heating hence it remains dissolved in water.

4. It can hydrogen bond with itself

At room temperature, benzoic acid can hydrogen bond with itself as well as with other molecules present in the same solution. This helps in making it more soluble in water. This property is due to the presence of two functional groups and polar character of the molecule.

5. It can form ionic bonds with ions.

Benzoic acid can form ionic bonds with other molecules present in the same solution. This property is due to the presence of two functional groups and polar character of the molecule. Benzoic acid can form ionic bond with water molecules and other polar compounds present in the solution such as fats (dipropyl myristate), proteins (diolefins), alcohols (benzyl alcohol) etc.. This polarity acts as an attractive force to attract benzoic acid towards itself as well as towards other positive charged ions present in the solution.

Uses of benzoic acid

1.Food preservative

This compound is used as a preservative in food products such as pickles, gums, jellies and jams to prevent their growth of microorganisms. Benzoic acid is used in medicine too. It is present in throat lozenges to treat sore throats and cough syrups to treat asthma and bronchitis.

2. Industrial use

Benzoic acid is mainly used as synthesis material in industries. It is used as plasticizer for nitrocellulose, plasticizer for polystyrene etc..

3. Pharmaceutical use

Benzoic acid is mainly used as glues and preservatives for treating wounds. It also acts as a mouth freshener. Benzoic acid is also used in making drugs, drug carriers, syrups etc..

4. Food additive

Benzoic acid is an important food additive in many countries around the world. This compound is used as a coloring agent and flavoring agent in confectionery, jams, jellies and soft drinks. The list of benzoic acid containing food products are too long to be here. They are also used in tanning agents, artificial leathers etc..

5. Pharmaceutical uses

It also acts as a preservative in medicines such as cough syrups, eye drops and inhalation drops for treating asthma bronchitis etc. It can be used as a stabilizer for hair dyes to prevent the formation of mixtures with acid. Benzoic acid is used in making drugs and drug carriers to protect drugs from rapid degradation during storage or transportation.

6. Laxative

Benzoic acid is also used as a laxative by people those affected by constipation and other similar problems. Consumption of Benzoic acid causes increased peristalsis of the intestine and thereby increases bowel movement. People use this drug in combination with other laxatives to relieve constipation faster. Since benzoic acid is a food additive it is consumed in food in small amounts but it also cause acidity (increase the pH value of blood) as well as sugar level to decline. It also decreases vitamin B1, vitamin D and calcium levels in the body.

Therefore it can be concluded that why is benzoic acid soluble in water is because it contains two functional groups, OH and C=O which when present together, form polar bond with water molecules therefore making it highly polar. Due to its high boiling point, benzoic acid will not evaporate in the presence of water and remains dissolved. It also has capability to hydrogen bond with itself as well as with other molecules present in the same solution.