The chemical name for baking soda is sodium hydrogen carbonate. It is also named as bicarbonate of soda or sodium bicarbonate.
It is an alkaline white substance that is slightly salty in taste. Its history dates back 4 million years ago when due to drought the salt lakes around the globe dried up resulting in deposits of trona.
The trona rock can be processed into soda ash which is chemically sodium carbonate and occurs naturally. It is also used for making baking soda.
Is baking soda a compound? Yes, baking soda is a compound. The chemical formula for baking soda is written as NaHCO3. This indicates that one molecule of sodium bicarbonate is formed by the combination of atoms of four different elements that are combined in a specific ratio viz. one atom of sodium (Na), one atom of hydrogen (H), one atom of carbon (C) and three atoms of oxygen (O). These atoms are chemically bonded together and cannot be separated using any physical process.
According to chemistry, a compound is a substance that is formed by the combination of two or more different types of atoms or ions that are bonded chemically in definite proportions.
As seen above, all these criteria are fulfilled by baking soda, therefore, it is a compound.
Is Baking Soda a Mixture?
As per the definition mixtures are the substances formed by blending of two or more different types of atoms or ions.
However, the mixtures are different from compounds as the different atoms or ions in a mixture is neither chemically bonded nor they are present in a specific ratio.
The atoms still exhibit their individual properties. Also, the components of a mixture can be easily separated from one another by physical processes.
However, the different atoms chemically bond in definite proportions to form a molecule of baking soda. Also, the properties of baking soda are different from any of its fundamental elements.
Hence, baking soda is not a mixture.
How is Baking Soda a Compound?
We have already discussed that baking soda is a compound but, what are the characteristics that actually make it a compound.
The atoms of sodium, hydrogen, carbon, and oxygen combine in the ratio of 1:1:1:3, respectively, for the formation of one molecule of baking soda.
These atoms give up their individual characteristics and together with other atoms acquire properties that are unique to baking soda.
It does not dissociate into its constituent elements through simple physical processes. All these are the features of a compound therefore, baking soda is a compound.
Sodium bicarbonate is an ionic compound in which the molecules break into separate ions viz. Na+ and HCO3- in an aqueous solution. Further dilution results in the formation of CO32- ions.
As the formation of ions is the property of compounds. Therefore, baking soda can be rightly called a compound.
Types of Compound
The compounds can broadly be classified into two categories viz. molecular or covalent compounds and ionic compounds.
As the name indicates these compounds are formed due to the formation of the covalent bond between different atoms.
These atoms are present in a specific ratio that remains the same throughout the substance. The molecules of these compounds are electrically neutral and do not dissociate in an aqueous solution.
The compounds that contain mostly carbon and hydrogen atoms are termed organic compounds and are mostly covalent in nature.
A few examples of covalent compounds are CH4, CO2, etc.
These are formed due to ionic bonding between different atoms of a molecule. These dissociate in an aqueous solution and are good conductors of heat and electricity.
The ratio of atoms is definite in these compounds. Most of the inorganic compounds are ionic. Examples include HCl, NaOH, NaHCO3, etc.
NaHCO3 is an amphoteric compound i.e. it can react as an alkali as well as an acid.
In an aqueous solution, it may give away a proton to react as an acid or may accept a proton and react as a base.
What is Baking Soda made of?
As clear from the chemical formula NaHCO3 baking soda is a compound of four elements viz. sodium, hydrogen, carbon, and oxygen.
The atoms of these elements combine in a definite proportion of 1:1:1:3 for the formation of one molecule of sodium bicarbonate.
The molecule of baking soda dissociates in an aqueous solution and form different ions. As discussed earlier it can react both as an acid as well as base, therefore, the ions formed are also different.
For an alkaline solution one molecule of baking soda breaks as follows:
NaHCO3 + H2O —-> Na+ + H2CO3 + OH-
While when reacting as an acid the following ions are formed:
NaHCO3 + H2O —> Na+ + CO3-2 + H3O+
Is Baking Soda a Heterogeneous Mixture?
The heterogeneous mixture is the one in which the constituent atoms are not distributed evenly i.e. the proportion of different atoms is not the same throughout the mixture resulting in the formation of different phases which do not intermix.
Usually, the phases can be differentiated visually. Also, like any other mixture, the components are not bonded chemically and can be easily separated.
A few examples of heterogeneous mixtures are vegetable soup, oil in water, etc.
The molecules of sodium bicarbonate have a definite proportion of all the combining atoms. Also, no separate phases are present here.
Therefore, baking soda is definitely not a heterogeneous mixture.
Is Baking Soda a Homogeneous Mixture?
In a homogeneous mixture the combining atoms although uniformly distributed but are not combined chemically. The composition of such mixtures is definite and uniform.
Separate phases may not be present but the individual properties of the different types of atoms remain unaltered.
Due to the inability of different atoms to form chemical bonds amongst them, the constituent elements may be separated through physical processes such as boiling.
A few examples of homogeneous mixtures are salt in water, sugar in water, etc.
The sodium bicarbonate molecules resemble homogeneous mixtures, as the combining atoms are present in definite and uniform proportions.
However, unlike homogeneous mixtures, the atoms in the molecules of baking soda are bonded chemically and cannot be separated through mere physical processes.
Therefore, baking soda is also not a homogeneous mixture.
A few important properties of baking soda are listed below:
• Baking Soda is also known as sodium bicarbonate or sodium hydrogen carbonate.
• It is a powdery substance with a monoclinic crystalline structure.
• It is denoted by the chemical formula NaHCO3.
• It has a molecular mass of 84.0066 g/mol.
• It is a non-flammable and non-explosive substance.
• It has a pH range between 8 and 9 and a pKa value of 6.3.
• It is non-corrosive alkali.
• It is an odorless substance and white in appearance.
• The density of baking soda is 2.20 g/cm3.
• The boiling and melting points of sodium bicarbonate are 851 °C and 50°C, respectively.
• It is amphoteric in nature i.e. it can behave both as an acid as well as a base in an aqueous solution.
• The refractive index of baking soda is 1.583.
• It has a heat capacity of 87.6 J/mol K and standard entropy of 101.7 J/mol K.
Various uses of baking soda are given below:
• The most important user of baking soda is in the bakery industry where it is used in the preparation of bread, cakes, etc. Here, it works as a leavening agent that releases carbon dioxide and helps in the rising of baked goods.
• It is used in pyrotechnics especially in a firework named as “black snake” where it produces ash in the shape like that of a snake as a result of thermal combustion.
• It is used as a fungicide, pesticide, and absorbing malodors.
• It forms the main component of fire extinguishers used in dousing electrical fire as it produces carbon dioxide in the presence of heat.
• It is used as a laundry detergent and also as a cleanser for swimming pools, fish tanks, etc. as it balances the pH because of its amphoteric nature.
• The antibacterial properties of baking soda make it an excellent kitchen cleaner.
• In the laboratory, it is also used for neutralizing various acids especially in the case of accidental spills.
• Along with water sodium bicarbonate works as an antacid and is used for treating issues such as acidity and heartburn.
• Baking soda also forms a part of deodorants and is used for absorbing the foul odor of refrigerators.
• Due to its abrasive and anticaries properties, it is also used in personal care products such as mouthwashes.
• It is used in the production of cosmetics, mouth and teeth cleaner, etc.
• It is also used in the polishing of silver articles.
• Baking soda is also added as a buffering agent in cattle feed supplements.
Baking soda is a compound as it is formed by the chemical bonding between different types of atoms in definite proportions.
The properties of baking soda are different from any of its constituent atoms and it cannot be separated into its basic components through physical processes, therefore, it is not a mixture.
Baking soda is an ionic compound that is amphoteric in nature i.e. it has the ability to behave as an alkali as well as an acid in an aqueous solution.
One molecule of sodium bicarbonate is formed by the combination of sodium, hydrogen, carbon, and oxygen atoms in a 1:1:1:2 ratio.