Carbonates and Bicarbonates

Many people confuse sodium carbonate and sodium bicarbonate; however, they are not the same substance. Even though both the compounds include sodium, their applications are quite different. As a byproduct of metabolism, the human body emits carbon dioxide. The majority of this CO2  is dissolved in the plasma and is present as bicarbonate. The carbonate and bicarbonate systems are primarily responsible for maintaining the pH of our blood, acting as a buffer in the process. Bicarbonate and carbonic acid are formed whenever carbon dioxide dissolves in water. Therefore, there is a balance between these compounds.

Sodium carbonate is chemically known as Na2CO3, while sodium bicarbonate is chemically known as NaHCO3.

Carbonate

• Carbonate is an inorganic ion composed of 3 oxygen atoms and 1 carbon atom. It carries a divalent charge in the negative direction (-2 electrical charge). 
• Carbonate ion is trigonal planar and weighs 60 g mol-1.
• Carbonate ions are formed when CO2  or bicarbonate dissolves in water. Carbonate compounds are essential components of the carbon cycle. 
• Carbonates are ionic chemicals that are water-insoluble.
• The chemical formula of Carbonate ion: CO32-–

Bicarbonate

• 1 hydrogen, 1 carbon, and 3 oxygen atoms form the monovalent anion known as bicarbonate. It is formed when carbonic acid is deprotonated. 
• It features a trigonal planar shape based on the carbon atom at its centre. The molecular weight of the bicarbonate ion is 61 g mol-1.
• Carbon dioxide can be converted to carbonate or bicarbonate in alkaline solutions. Carbonates usually occur when modest amounts of CO2  pass through alkaline solutions. 
• On the other hand, bicarbonates are formed when enough carbon dioxide is dissolved in the solution.
• Carbonic acid has a conjugate base in the form of bicarbonate. The carbonate ion’s conjugate acid and carbonic acid’s conjugate base are bicarbonate, which occurs naturally as an alkaline compound. 
• Ionic salts are formed when positively charged ions mix with negative charges oxygen in this ion. The most common bicarbonate salt is sodium bicarbonate, which we commonly refer to as baking powder. 
• Additionally, when bicarbonate compounds react with acids, carbon dioxide is produced.
• The chemical formula of Bicarbonate ion: HCO3-

Unique Features:

• At room temperature, carbonates and bicarbonates are solids. Carbonates of elements in groups 1 and 2 are colourless because the carbonates of transitional elements can be coloured.
• Group-1 metal ions (M+) have lower polarising power than group-2 metal ions (M2+). As a result, group 2 has higher covalent bonds than carbonates in group 1.
• On the other hand, as the size of the metal ion increases, the polarising power diminishes as one moves down the group. As a result, the ionic nature increases as the group size decreases.
• Both NaHCO3 and KHCO3 are solids. However, group-2 element bicarbonates are only recognized in aqueous solutions.
• With the exception of Li2CO3, group-1 carbonates are relatively water-soluble as the ionic nature of the compound increases, the solubility increases.
• Group-2 carbonates are less water-soluble due to greater lattice energy. In this category, there is no noticeable trend in the solubility of the compounds.
• However, due to the production of HCO3- , group-2 carbonates are soluble in a solution of CO2 .
• When heated, carbonates disintegrate into carbon dioxide and oxide. On the other hand, Bicarbonates produce carbonate, water, and carbon dioxide.
• As the polarising activity of the metal ion decreases, the thermal conductivity of group-1 & group-2 carbonates (as well as bicarbonates) increases.
• For the same reason, group-1 carbonates are much more stable than group-2 carbonates.
• Small and highly charged metal ions have greater polarising power than larger and less charged metal ions, which allows for a more efficient breakdown of carbonate ions into carbon dioxide and oxide ions.

Carbonate Vs. Bicarbonate: What’s The Difference?

• While carbonate and bicarbonate have similar physical features, chemically, carbonates and bicarbonates’ meanings are very different.
• Carbonate is a -2 charge divalent anion. Bicarbonate is a single-valent anion composed of one carbon, three oxygen atoms, and one hydrogen atom. In the process of deprotonation, it turns into carbonic acid.
• Their charge distinguishes carbonate and bicarbonate, meaning; carbonate has a -2 charge, whereas bicarbonate has a -1 charge.
• Because bicarbonate contains hydrogen atoms, its molecular weight is 61 g/mol, while carbonate is 60 g/mol.
• Carbonate ions are more prevalent in highly alkaline environments, whereas bicarbonate ions are more prevalent in weakly alkaline environments.
• Carbonate is insoluble in water at standard temperature and pressure, but bicarbonate is freely soluble in water.

Conclusion

• As a weak acid, bicarbonate has carbonate as a conjugate base. Carbon and oxygen atoms combine to form the ions carbonate and bicarbonate. 
• However, the bicarbonate ion also contains a hydrogen atom. As a result of this hydrogen atom, the ion transforms into monovalent anions, whereas the carbonate remains a divalent anion. 
• As a result, the most significant distinction between the ions carbonate and bicarbonate would be that the carbonate has a negative electrical charge, whereas the bicarbonate ion has a positive electrical control.
• Baking soda and baking powders are sodium carbonate and bicarbonates. When it comes to cookies and cakes, baking soda is used to level the substance, while baking powder is utilised for complete levelling and longer-term storage of the finished product.