Potassium sodium carbonate, K₂CO₃,Na₂CO₃,12H₂O, or (K, Na)₂CO₃,12H₂O

A Potassium sodium carbonate, K₂CO₃,Na₂CO₃,12H₂O, is a constituent of vegetable ashes. At 35° C. it decomposes in accordance with the equation

3(K₂CO₃,Na₂CO₃,12H₂O) = 2K₂CO₃ + K₂CO₃,3Na₂CO₃,10H₂O + 26H₂O.

The double carbonate thus generated decomposes at a temperature of about 130° C.