The dehydration of sodium carbonate decahydrate (Na₂CO₃·10H₂O) can be represented by the following equation:

Na₂CO₃·10H₂O(s) → Na₂CO₃(s) + 10H₂O(g)

This equation shows that when sodium carbonate decahydrate is heated, it loses its ten water molecules as water vapor, leaving behind anhydrous sodium carbonate.