1, thermal stability: sodium carbonate does not decompose when heated, and sodium bicarbonate is easily decomposed into sodium carbonate, water and carbon dioxide when heated;

2. Water solubility: the solubility of sodium carbonate is greater than that of sodium bicarbonate;

3. Reaction with carbon dioxide: sodium carbonate can combine with carbon dioxide (and water) to generate sodium bicarbonate, but sodium bicarbonate does not react;

4. Reaction with sodium hydroxide: sodium bicarbonate can react with sodium hydroxide to generate sodium carbonate and water, but sodium bicarbonate does not react;

5. Reaction with calcium chloride: sodium carbonate and calcium chloride (or barium chloride) solution are easy to generate carbonate precipitation, while sodium bicarbonate and dilute salt solution are not easy to generate precipitation. 6. Reaction with phenol: Sodium carbonate can react with phenol to produce sodium phenolate and sodium bicarbonate, while sodium bicarbonate does not react with phenol.