Turn Baking Soda into Washing Soda

[Keylin1994]

I'm trying out something I read on the internet about Turing baking soda into washing soda. It's really simple...pretty much just pour some baking soda in a pan and bake at 400. The chemistry I read about seems to be sound. The heat liberates the bound water molecule in the sodium bicarbonate causing it to become sodium carbonate, or washing soda/soda ash.

Has anyone else tried this?

 

[jblizzle]

Welcome to TFP!!!

Nope. And not sure why you would want to

 

[chem geek]

The claim is that when baking soda gets heated it turns into washing soda, carbon dioxide, and water. Let's see if that makes sense:

2NaHCO₃ + heat ---> Na₂CO₃ + H₂O + CO₂
Baking Soda + heat ---> Washing Soda + Water + Carbon Dioxide

This balances correctly and another way of looking at it is the following:

2NaHCO₃ + heat ---> Na₂CO₃ + H₂CO₃
Baking Soda + heat ---> Washing Soda + Carbonic Acid

Basically, adjacent baking soda crystals can exchange sodium and hydrogen and the carbonic acid can form separate water and carbon dioxide that both outgas from the heat. The above process is actually one step in the Solvay Process that starts with calcium carbonate (limestone) and uses ammonia and sodium chloride salt to produce sodium carbonate (washing soda) and calcium chloride with the ammonia regenerated since its use is as an intermediate (catalyst).

 

[JamesW]

General Fire Hazards
If extremely large quantities of Sodium Bicarbonate are involved in a fire, significant levels of carbon dioxide may be generated. Soda ash (sodium carbonate), another decomposition product resulting from heating above 200 deg F, is a respiratory, skin, and eye irritant.

Hazardous Combustion Products
When heated to decomposition Sodium Bicarbonate emits acrid smoke, fumes, and carbon dioxide and sodium oxides.

From an MSDS.