Washing Soda and Baking Soda : Difference and Properties
Washing Soda
The chemical name of washing soda is Sodium Carbonate. It is found in three forms, washing soda, crystalline carbonate and soda ash.
It is found in abundance in the form of reh or sajji soil on the surface of the earth at various places in uttar pradesh, bihar and rajsthan in India.
To obtain washing soda, carbon dioxide gas is passed through a concentrated solution of caustic soda. This gives a solution of sodium carbonate, on evaporation of which crystals of sodium carbonate are obtained.
2NaOH + CO₂ → Na₂CO₃ + H₂O
Washing Soda Properties
There are main physics and chemical properties as follows.
Physics Properties
- Washing soda is an odorless, white crystal substance in which one molecule contains 10 molecules of crystal water.
- It dissolves in water and provides enough heat.
- By keeping it in dry air, the crystal water molecules come out and on heating, anhydrous sodium carbonate is formed.
Chemical Properties
Heat effect: On heating crystal sodium carbonate, it turns into anhydrous sodium carbonate.
Na₂CO₃.10H₂O → Na₂CO₃ + 10H₂O
Reaction with carbon dioxide: – On passing CO2 gas in its aqueous solution, a precipitate of sodium bicarbonate is obtained.
Na₂CO₃ + H₂O + CO₂ → 2NaHCO₃
Reaction with water :- This water decomposes to give alkaline solution.
Na₂CO₃ + 2H₂O → 2NaOH + H₂CO₃
Reaction with Acids: – When sodium carbonate reacts with an acid, salt and water of that acid are obtained. Carbon dioxide gas is also liberated as a result of the reaction.
Na₂CO₃ + H₂SO₄ → Na₂SO₄ + H₂O + CO₂
Reaction with slaked lime :- When washing soda is boiled with slaked lime or calcium hydroxide [Ca(OH)2], causting soda is formed.
Na₂CO₃ + 2H₂O → 2NaOH + H₂CO₃
Reaction with Sulfur dioxide :- On passing sulfure dioxide (SO₂) gas in an aqueous solution of sodium carbonate, first sodium sulfite (Na₂SO₃) is formed which is later converted into sodium bysulfite (NaHSO₃).
Na₂CO₃ + Ca(OH)₂ → 2NaOH + CaCO₃
Lead manufacture :- On melting the mixture of sodium carbonate and sand, sodium silicate is formed, which is called soluble lead, because it is soluble in water.
Na₂CO₃ + SO₂ → Na₂SO₃ + CO₂
Na₂SO₃ + H₂O + SO₂ → 2NaHSO₃
Reaction with metal salts: On heating metal salts with sodium carbonate, metallic carbonates are formed.
BaCl₂ + Na₂CO₃ → BaCO₃ + 2NaCl
But salts like ZnSO₄, Pb(NO₃)₂ give a precipitate of basic carbonate.
3Pb(NO₃)₂ + 3Na₂CO₃ + H₂O → [2PbCO₃.Pb(OH)₂] + 6NaNO₃
Washing Soda Uses
- As a reagent in the laboratory.
- To soften hard water.
- In lead, paper and soap business.
- In washing clothes and removing the greasiness of glass utensils.
- Baking powder, casting soda, pent and in making icing
- In the refining of petroleum.
- In the extraction of metals.
Baking Soda (Sodium Bicarbonate)
Banking soda is obtained by passing carbon dioxide (CO₂) gas into a solution of sodium carbonate (Na₂CO₃).Na₂CO₃ + H₂O + CO₂ → 2NaHCO₃
Properties of Sodium Bicarbonate
Physical properties :
- Sodium bicarbonate is a white crystal substance.
- It is soluble in water in small amounts. Its solution is alkaline.
- Mixing it in raw milk causes the milk to burst late.
Chemical Properties :
Heat effect: On heating up to 100°C, it decomposes into sodium carbonate.
2NaHCO₃ → Na₂CO₃ + H₂O + CO₂
Reaction with Acids:- It reacts with dilute acids to form salt and water and carbon di oxide gas is evolved.
NaHCO₃ + HCl → NaCl + H₂O + CO₂
2NaHCO₃ + H₂SO₄ → Na₂SO₄ + 2H₂O + 2CO₂
Banking soda uses
- As a medicine in case of acidity in the stomach.
- In fire extinguishers.
- In making cold drinks, sodawater and fruit salt.
- As reagent in laboratory.
- Used in the preparation of baking powder in double bread.
- In making foaming pills and seidlitze power for family planning.
- In making sodium carbonate.