Baking soda And Others

Sodium bicarbonate, also known as baking soda or bicarbonate of soda, is a chemical compound with the formula NaHCO₃ and the IUPAC designation sodium hydrogencarbonate. A sodium cation (Na⁺) and a bicarbonate anion (HCO₃) combine to form this salt. Sodium bicarbonate is a white, crystalline substance that is commonly found as a fine powder. It tastes slightly salty and alkaline, like washing soda (sodium carbonate).

Chemical name – Sodium hydrogen carbonate
Chemical formula – NaHCO₃

Preparation (Solvay process):
a. Limestone is heated: CaCO₃→CaO+CO₂
b. CO₂ is passed through a concentrated solution of sodium chloride and ammonia:
NaCl(aq)+NH₃(g)+CO₂(g)+H₂O(l)→NaHCO₃(aq)+NH₄Cl(aq)

Uses:

• Reduces the acidity in the stomach
• Acts as an antacid which is used to treat stomach upset and indigestion
• Used in the process of washing as a water softener

Washing soda

Chemical name – Sodium hydrogen carbonate
Chemical formula – NaHCO₃
Preparation (Solvay process) – 
a. Limestone is heated: CaCO₃ → CaO + CO₂
b. CO₂ is passed through a concentrated solution of sodium chloride and ammonia:
NaCl(aq) + NH₃(g) + CO₂(g) + H₂O(l) → NaHCO₃(aq) + NH₄Cl(aq)

Uses
1. In glass, soap and paper industries
2. Softening of water
3. Domestic cleaner

Crystals of salts

Certain salts form crystals by combining with a definite proportion of water. The water that combines with the salt is called water of crystallisation.

The process by which a solid forms, in which the atoms or molecules are strongly arranged into a structure known as a crystal, is known as crystallisation. Precipitation from a solution, freezing, and, more rarely, direct deposition from a gas are some of the ways crystals form.

Example:

Table salt (sodium chloride or halite crystals), sugar (sucrose), and snowflakes are examples of common materials that form crystals. Many gemstones, such as quartz and diamond, are crystals.