Carbonic acid (H2CO3) is formed when carbon dioxide dissolves in water, and it plays a crucial role in regulating the pH of the oceans and controlling the weathering of rocks.
| IUPAC Name | Carbonic acid |
| Molecular Formula | H2CO3 |
| CAS number | 463-79-6 |
| Synonyms | Acid of air; Aerial acid; H2CO3; Oxidaniumylidenemethane; Acid carbonate; hydroxy ketone; Dihydroxymethanone |
| InChI | InChI=1S/CH2O3/c2-1(3)4/h(H2,2,3,4) |
Carbonic acid formula
The chemical formula for carbonic acid is H2CO3, which indicates that it is composed of two hydrogen atoms, one carbon atom, and three oxygen atoms. The formula also shows the ratio of the atoms in the molecule, which is important in determining the stoichiometry of chemical reactions involving carbonic acid.
Carbonic acid molar mass
The molar mass of carbonic acid is approximately 62.03 g/mol. It is a weak acid that is formed when carbon dioxide dissolves in water and is responsible for regulating the pH of the oceans. The molar mass of carbonic acid is important in calculating the amount of acid needed to reach a certain pH level in a solution, and in determining the amount of carbon dioxide that can dissolve in water.
Carbonic acid boiling point
Carbonic acid does not have a well-defined boiling point, as it decomposes into water and carbon dioxide before it reaches its boiling point. However, at atmospheric pressure, carbonic acid decomposes at a temperature of about 333 K (60 °C) into the water and carbon dioxide.
Carbonic acid melting point
Carbonic acid also does not have a well-defined melting point, as it decomposes into water and carbon dioxide before it reaches its melting point. However, at atmospheric pressure, carbonic acid decomposes at a temperature of about 273 K (-0.15 °C) into the water and carbon dioxide.
Carbonic acid density g/ml
The density of carbonic acid is approximately 1.67 g/mL at room temperature (25 °C). This value can vary depending on the concentration of the solution, as well as the temperature and pressure of the environment.
Carbonic acid Structure
Carbonic acid has a tetrahedral molecular geometry, with the carbon atom at the center and the four surrounding atoms (two oxygen and two hydrogens) located at the corners of a tetrahedron. The two oxygen atoms are bonded to the carbon atom through double bonds, while the two hydrogen atoms are bonded through single bonds.
Carbonic acid molecular weight
The molecular weight of carbonic acid is 62.03 g/mol. This value is calculated by adding the atomic weights of the constituent elements, which are hydrogen (H), carbon (C), and oxygen (O).
| Appearance | Colorless liquid or crystalline solid |
| Specific Gravity | 1.67 g/cm³ |
| Color | Colorless |
| Odor | Odorless |
| Molar Mass | 62.03 g/mol |
| Density | 1.67 g/mL at room temperature (25 °C) |
| Melting Point | Decomposes at around 273 K (-0.15 °C) |
| Boiling Point | Decomposes at around 333 K (60 °C) |
| Flash Point | Not applicable |
| Water Solubility | Completely soluble |
| Solubility | Soluble in water, ethanol, methanol |
| Vapor Pressure | Not applicable |
| Vapor Density | Not applicable |
| pKa | 3.6 (first dissociation) |
| pH | 5.6 (in 0.1 M solution) |
Carbonic acid Safety and Hazards
Carbonic acid (H2CO3) is generally considered to be safe, but it can pose some hazards in certain situations. Exposure to H2CO3 can cause irritation to the eyes, skin, and respiratory system, and can lead to coughing, wheezing, and shortness of breath. The ingestion of H2CO3 can cause stomach discomfort, nausea, and vomiting. H2CO3 is also a weak acid and can react with certain metals, such as aluminum and zinc, to produce flammable hydrogen gas. When handling or using H2CO3, appropriate safety measures should be taken, including wearing protective clothing and ensuring proper ventilation. In case of exposure, medical attention should be sought immediately.
| Hazard Symbols | None |
| Safety Description | Non-toxic |
| UN IDs | UN 1824 |
| HS Code | 28111990 |
| Hazard Class | 8 – Corrosive substances |
| Packing Group | III |
| Toxicity | Low toxicity |
Carbonic acid Synthesis Methods
H2CO3 can be synthesized through a number of different methods. One common method is to react carbon dioxide (CO2) with water (H2O) in the presence of a catalyst. This process, known as hydration, produces carbonic acid:
CO2 + H2O → H2CO3
Another method of synthesizing carbonic acid is through the reaction of calcium carbonate (CaCO3) with an acid, such as hydrochloric acid (HCl). This process, known as acidification, produces carbonic acid:
CaCO3 + 2HCl → CaCl2 + CO2 + H2O
The reaction between oxalic acid and a carbonate, such as sodium carbonate (Na2CO3), can synthesize carbonic acid. This process produces carbonic acid and a salt, such as sodium oxalate:
H2C2O4 + Na2CO3 → 2H2CO3 + Na2C2O4
The Solvay process produces carbonic acid and sodium bicarbonate through the reaction of soda ash (Na2CO3) with carbon dioxide in the presence of water.
2NaHCO3 + CO2 → Na2CO3 + H2CO3
Overall, there are several methods available for the synthesis of carbonic acid, each with its own advantages and limitations. The choice of method will depend on factors such as the desired purity of the product, the availability of starting materials, and the scale of production required.
Carbonic acid Uses
Carbonic acid (H2CO3) is a versatile compound that finds a variety of uses in industry, medicine, and everyday life. Some of the major uses of H2CO3 include:
- Carbonated beverages: H2CO3 is the compound responsible for the characteristic fizz in carbonated beverages such as soda and beer.
- H2CO3 buffers pH in a variety of industrial processes, such as water treatment and food processing.
- It suppresses fire by displacing oxygen and preventing combustion.
- H2CO3 inhibits the growth of bacteria and mold in certain types of food products to preserve them.
- It acts as a mild cleaning agent, particularly for removing mineral deposits.
- Medical professionals use H2CO3 in certain applications, including treating some skin lesions and inducing bronchial constriction during pulmonary function testing.
- Welders use H2CO3 as a shielding gas to prevent oxidation and produce cleaner welds.
Overall, carbonic acid is a useful and versatile compound that has a wide range of applications in various fields.
Questions:
Q: Is carbonic acid a strong acid?
A: Carbonic acid is a weak acid, meaning that it only partially dissociates in water to produce hydrogen ions (H+) and bicarbonate ions (HCO3-). Its acid dissociation constant (Ka) is relatively low, indicating that it does not completely dissociate in water.
Q: Is carbon dioxide acidic?
A: Carbon dioxide (CO2) is not inherently acidic, as it is a neutral compound that does not produce hydrogen ions (H+) in water. However, when CO2 dissolves in water, it can react with the water molecules to form carbonic acid, which is a weak acid. This reaction can lead to a decrease in pH, making the solution more acidic. Therefore, although CO2 itself is not acidic, it can contribute to the acidity of a solution when it reacts with water.