Principle:
The reaction relies on the principle of double displacement, where the cations and anions of two reactants switch partners to form two new products.
Steps:
1. Reaction: Barium nitrite (Ba(NO2)2) is reacted with sodium sulfate (Na2SO4) in an aqueous solution.
2. Precipitation: The reaction produces insoluble barium sulfate (BaSO4) as a precipitate, while sodium nitrite (NaNO2) remains dissolved in the solution.
3. Separation: The precipitate is separated from the solution through filtration.
4. Evaporation: The solution containing sodium nitrite is evaporated to obtain solid sodium nitrite.
Chemical Equation:
Ba(NO2)2 (aq) + Na2SO4 (aq) → BaSO4 (s) + 2 NaNO2 (aq)
Important Considerations:
* Purity of Reactants: Using high-purity barium nitrite and sodium sulfate is crucial for obtaining pure sodium nitrite.
* Safety Precautions: Barium salts are toxic, so proper handling and disposal procedures are essential.
* Yield and Efficiency: The reaction's yield and efficiency depend on the reaction conditions and the purity of the reactants.
Alternative Method:
Another way to obtain sodium nitrite is through the reaction of nitric acid with sodium hydroxide followed by reduction with a reducing agent like sulfur dioxide.
Note: Manufacturing sodium nitrite is generally not carried out on a large scale in home laboratories due to the safety concerns and availability of readily available commercial sodium nitrite.
