Advanced Topic 627 of 1102 Inorganic Chemistry
Solvay Process
Produces sodium carbonate from brine, ammonia and limestone.
In-depth explanation of Solvay Process
The Solvay process makes sodium carbonate, also called soda ash, from brine, ammonia and limestone. Carbon dioxide from heated limestone is bubbled through ammonia-saturated brine, and sodium hydrogencarbonate, which is much less soluble, precipitates: NaCl + NH3 + CO2 + H2O giving NaHCO3 + NH4Cl. Heating the precipitate decomposes it to sodium carbonate and recycles the CO2. Ammonia is regenerated with lime, so the only waste is calcium chloride. The process replaced the less efficient and more polluting Leblanc process.
Going deeper: Solvay Process
Key ideas: Raw materials are NaCl, NH3 and CaCO3. Steps: NH3 + CO2 + H2O + NaCl gives NaHCO3 (precipitates, low solubility) + NH4Cl; heating NaHCO3 gives Na2CO3; CaCO3 calcined gives CaO and CO2; CaO with NH4Cl regenerates NH3. Overall: CaCO3 + 2NaCl gives Na2CO3 + CaCl2. Ammonia is recycled, so only CaCl2 is waste.
Common mistakes and connections: Students think K2CO3 can be made the same way, but KHCO3 is too soluble to precipitate. Another error is believing NH3 is consumed; it is recycled. Ammonia makes the brine basic so CO2 dissolves more. Connects to solubility product, Le Chatelier principle and green chemistry atom economy.
Visualization of Solvay Process
Precipitation of the sparingly soluble NaHCO3 pulls the equilibrium NaCl + NH3 + CO2 + H2O to NaHCO3 + NH4Cl forward in the Solvay process. The interactive lesson shows this as a live animation or chart.
Worked example and use case
Heating 2 mol of NaHCO3 gives 1 mol of Na2CO3, 1 mol of water and 1 mol of CO2.
Frequently asked questions about Solvay Process
What is Solvay Process?
Produces sodium carbonate from brine, ammonia and limestone.
Is Solvay Process a beginner, intermediate or advanced topic?
Solvay Process is a advanced topic in Inorganic Chemistry. It builds on beginner and intermediate topics, so review those first if needed.
What should I learn before Solvay Process?
Study these earlier topics in Inorganic Chemistry first: Flame Tests, Sodium Chemistry, Sodium Hydroxide Production.
What comes after Solvay Process?
The next topics in Inorganic Chemistry are Alkaline Earth Metals and Calcium Compounds.
Can I practise Solvay Process with quizzes?
Yes. The interactive lesson includes a self-check question on Solvay Process, and the Inorganic Chemistry quiz draws on every topic in this area.
Where Solvay Process fits in Inorganic Chemistry
Solvay Process is topic 12 of 113 in Inorganic Chemistry.