Difference Between Sodium Carbonate and Sodium Hydrogen Carbonate

The key difference between sodium carbonate and sodium hydrogen carbonate is that the sodium carbonate powder is hygroscopic whereas the sodium hydrogen carbonate powder is not hygroscopic.

Both sodium carbonate and sodium hydrogen carbonate are alkaline, salt compounds. But they differ in chemical and physical properties. As for physical properties, the hygroscopic nature of sodium carbonate is the main difference. But when considering the chemical properties, the major difference between sodium carbonate and sodium hydrogen carbonate is the presence of hydrogen in the chemical structure of sodium hydrogen carbonate; sodium carbonate has no hydrogen atoms.

CONTENTS

1. Overview and Key Difference
2. What is Sodium Carbonate
3. What is Sodium Hydrogen Carbonate
4. Side by Side Comparison – Sodium Carbonate vs Sodium Hydrogen Carbonate in Tabular Form
5. Summary

What is Sodium Carbonate?

Sodium carbonate is a salt having the chemical formula Na2CO3. It has the common names, “washing soda” and “soda ash”. This salt is highly water-soluble. Moreover, it is hygroscopic. It means this compound can absorb water vapor from the air when we expose it to normal air.

Usually, this compound occurs as the decahydrate form. It is a crystalline compound that can readily undergo effloresce; then it forms the monohydrate form. Also, the sodium carbonate has a strong alkaline taste. When we dissolve this compound in water, it forms a basic solution. In its anhydrous form, the molar mass is 105.98 g/mol. The melting point is 851 °C, and it has no boiling point since it undergoes thermal decomposition upon heating.

Uses of sodium carbonate:

• As a water softener in laundering
• Used in the manufacturing of glass, paper, rayon, soaps, and detergents
• As a food additive
• To be used a substitute for lye-water in China
• As a wetting agent in the brick industry
• To clean silver
• To maintain pH and carbonate hardness in some aquariums

What is Sodium Hydrogen Carbonate?

Similarly, sodium hydrogen carbonate is a salt having the chemical formula NaHCO3. The common name for this compound is “baking soda”. The common chemical name is sodium bicarbonate. It occurs as a white solid that is crystalline but appears as a fine powder. Moreover, it has an alkaline taste that resembles sodium carbonate, and is water soluble but is poorly soluble when compared to sodium carbonate. The molar mass is 84 g/mol. It has no melting or boiling point because it starts to convert into sodium carbonate at 50 °C.

Uses of sodium hydrogen carbonate:

• Useful in cooking as a leavening agent for bakery products
• Used to make baking powder
• As a pest control: to kill cockroaches
• We can use it to raise the alkalinity of pool water
• As a mild disinfectant
• For the neutralization of acids or bases; due to its amphoteric properties

What is the Difference Between Sodium Carbonate and Sodium Hydrogen Carbonate?

Among these two compounds, sodium carbonate is a salt having the chemical formula Na2CO3. It has two sodium atoms and no hydrogen atoms per molecule. The molar mass of this compound is 105.98 g/mol. Moreover, the melting point is 851 °C and sodium carbonate has no boiling point since it undergoes thermal decomposition upon heating. On the other hand, sodium hydrogen carbonate is a salt having the chemical formula NaHCO3. It has one sodium atom and one hydrogen atom per molecule. The molar mass of this compound is 84 g/mol. Moreover, it has no melting or boiling point because it starts to convert into sodium carbonate at 50 °C. The key difference between sodium carbonate and sodium hydrogen carbonate is that the sodium carbonate powder is hygroscopic whereas the sodium hydrogen carbonate powder is not hygroscopic.

Summary – Sodium Carbonate vs Sodium Hydrogen Carbonate

Sodium carbonate and sodium hydrogen carbonate are salts of sodium. The key difference between sodium carbonate and sodium hydrogen carbonate is that sodium carbonate powder is hygroscopic whereas the sodium hydrogen carbonate powder is not hygroscopic. Furthermore, sodium hydrogen carbonate has a hydrogen atom in its chemical structure whereas sodium carbonate has no hydrogen atoms.

Reference:

1. “Sodium Carbonate.” National Center for Biotechnology Information. PubChem Compound Database, U.S. National Library of Medicine. Available here 
2. “Sodium Bicarbonate.” Wikipedia, Wikimedia Foundation, 25 July 2018. Available here 

Image Courtesy:

1.’Uhličitan sodný’By Ondřej Mangl – Own work, (Public Domain) via Commons Wikimedia  
2.’Sodium bicarbonate’By Thavox – Own work, (Public Domain) via Commons Wikimedia