Preparation of washing soda by solvay’s process

• The Solvay process is extensively used for industrial preparation of sodium carbonate (soda ash). The process is named after Ernest Solvay who developed the process during the 1860s.
• Carbon dioxide reacts with the dissolved ammonia to form ammonium carbonate followed by ammonium hydrogen carbonate.

2NH₃ +H₂O + CO₂ —> (NH₄)₂CO₃

(Ammonia)                 (Ammonium Carbonate)

(NH₄)₂CO₃ + H₂O + CO₂ –> NH₄HCO₃

(Ammonium Carbonate)       (Ammonium hydrogen carbonate)

NH₄HCO₃       +          NaCl  –>   NH₄Cl     +    NaHCO₃

Sodium hydrogen carbonate crystal separates. These are heated to give sodium carbonate.

     2 NaHCO₃       –>      Na₂CO₃ + CO₂ + H₂O

But this process cannot be used to prepare potassium due to the high solubility of potassium bicarbonate and hence difficult to be precipitated by adding ammonium bicarbonate to a saturated solution of potassium

Caustic Soda

• The chemical name of caustic soda is Sodium Hydroxide (NaOH).

Atomic and Ionic Radii of alkaline earth metal

• The atomic and ionic radii of the alkaline earth metals are smaller than alkali metals due to the increased nuclearcharge in these elements.
• Theatomic and ionic radii increase with increase in atomic number within a group.