In this article, “is baking soda ionic or covalent”, covalent or ionic properties of baking soda and lewis structure with detailed explanations are explained briefly.
Baking soda or sodium hydrogen carbonate, which is composed with sodium and bicarbonate ion, is definitely an ionic compound. It is a solid crystalline substance with slightly alkaline nature in aqueous solution due to production of carbonic acid and hydroxide ion. It basically shows amphoteric property.
Main outlook of this article to explain baking soda as an ionic compound is described below.
Characteristics of an ionic and covalent compound
Ionic Compound
- Electrons are completely transferred from less electronegative atom to more electronegative atom in any ionic compound.
- Atoms which are participating in formation of ionic bond are generally the combination of one metal and another nonmetal.
- Ionic compounds have higher melting and boiling point than the covalent compounds.
- They have high vapourization and fusion enthalpies than the respective compounds.
- Ionic compounds are good conductor. They conduct electricity when dissolves in water or any aqueous solution.
Image Credit: Wikimedia Commons.
Covalent Compound
- Like ionic compounds electrons are not completely transferred rather it is shared between the covalent bond forming atoms.
- They have relatively lower melting and boiling point with lower vapourization and fusion enthalpies.
- Flexibility and softness in one more important properties of covalent compound.
- They are more flammable than ionic compounds.
- They don’t conduct electricity after dissolving in aqueous solution.
Image Credit: Wikipedia.
To know more please follow: Triple Bond Examples: Detailed Insights And Facts
How is baking soda ionic?
Sodium bicarbonate was first synthesized by French chemist, Nicolas Leblanc in 1971. Baking soda is an ionic compound. It is consisted with two ions, sodium ion (Na+) and bicarbonate ion (HCO3–) in equal amount.
In baking soda, sodium is a metal and carbonate is a group of atoms having negatively charged. In bicarbonate ion, the carbon, hydrogen and oxygen atoms are attached by covalent bonds with each other. But, in sodium bicarbonate an ionic interaction is present between sodium cation and bicarbonate anion.
Like any other ionic compound, sodium carbonate also has a low enthalpy of formation (-950.8 KJ/mol). It also has a crystalline structure (monoclinic) with a high boiling point 8510 C.
In industry, sodium bicarbonate is prepared from soda ash, known as sodium carbonate (Na2CO3) by dissolving in water and reacting with carbon dioxide gas (CO2). As baking soda is less soluble in water, so it can be easily crystallized and separated from water.
Na2CO3 + CO2 + H2O = 2NaHCO3
In aqueous solution, sodium bicarbonate shows some alkaline property due to production of weak carbonic acid (H2CO3) and hydroxide ions (OH–).
HCO3– + H2O = H2CO3 + OH–
Image Credit: Wikimedia Commons.
To know more please check: 4 Single Covalent Bond Examples : Detailed Insights And Facts
Why Baking soda is not a covalent compound?
There are four covalent bonds in bicarbonate ion (HCO3–) between oxygen, carbon and hydrogen atoms. But sodium and bicarbonate ion are attached by strong ionic interaction.
Bicarbonate ion (HCO3–) is expressed as the resonance hybrid structure of two structure. Covalent bonds generally formed between two nonmetals. But in baking soda sodium is a metal and bicarbonate is a group of nonmetal atoms, which is one of the properties of ionic compound. In covalent compounds, none of the bond forming atoms get positively or negatively charged due to not permanent transferring electrons like ionic compounds. Electrons are only shared between atoms in covalent compounds. But in baking soda sodium gets positively charged and bicarbonate gets negatively charged.
A relatively high electronegativity difference between two atoms or groups must be present in ionic compound. Due to presence of two opposite charge (Na+ and HCO–3), there is a huge electronegativity difference in baking soda, which is not a property of covalent compound.
To know more please read: Is O2 a triple bond: Why, How, Characteristics and Detailed Facts
Baking Soda Lewis structure
Lewis structure or lewis dot structures is a way to express the outer most shell electrons of atoms as well as the electrons participating in bond formation with other atoms.
Thus, to know the number of covalent or ionic bonds forming in any chemical species as well as the electrons not participating in any bond formation (nonbonded electrons), Lewis dot structure is very much helpful. It also helps to determine the formal charge of each of the atoms in any species.
QF = NV – Nnb – Nbe /2
In this above formula-
- QF = Formal charge of the respective atoms
- NV = Number of valance shell electrons of that atom in free stage
- Nnb = Number of nonbonded electrons
- Nbe = Number of electrons participating in bond formation.
To draw the lewis structure of any species, valance electrons of each of the atoms and the total bonds present in that molecular species must be known.
In baking soda, sodium has one valance electrons (1s2 2s2 2p6 3s1) and the valance shell electrons of bicarbonate ion is shown around the each of the atoms.
To know more please go through: 5 Polar Covalent Bond Examples: Detailed Insights And Facts
Frequently Asked Questions (FAQ)
Is sodium bicarbonate soluble in water?
Answer: Sodium bicarbonate is soluble in water but solubility in water is very much less (96g/l in 200 C) because the density of water is greater than the density of sodium bicarbonate.
What are the uses of baking soda in our daily life?
Answer: It has the following uses in our daily life.
- It has the capability to reduce the acidity in stomach.
- Sodium bicarbonate is also used as washing element.
- It also acts as pesticides.
- Sodium bicarbonate has a significance use in ear drop and personal skin care products.
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I am Aditi Ray, a chemistry SME on this platform. I have completed graduation in Chemistry from the University of Calcutta and post graduation from Techno India University with a specialization in Inorganic Chemistry. I am very happy to be a part of the Lambdageeks family and I would like to explain the subject in a simplistic way.
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