How to distinguish between Na2CO3 and NaHCO3 by a chemical test? $\ce{Na2CO3}$ and $\ce{NaHCO3}$ have similar reactions. For example, they can react with acid to produce $\ce{CO2}$.
So my question is:  


  Can we use a chemical test to distinguish between $\ce{Na2CO3}$ and $\ce{NaHCO3}$?  




I know that $\ce{NaHCO3}$ can be thermal decomposed into $\ce{Na2CO3}$ via this reaction: $2\ce{NaHCO3-&gt;} \ce{Na2CO3} + \ce{CO2} + \ce{H2O}$
However, I am not sure if thermal decomposition is a chemical test.
Heating salt is an important test in determining the anion in the salt by checking the gas evolved. This test is called dry heating test and is a important part of qualitative analysis of salt. But this test goes under physical examination of salt (checking color, appearence etc.).

One important chemical test to differentiate carbonate and bicarbonate is $\ce{MgSO4}$  test. 

$$\ce{Na2CO3 + Mg^2+ -&gt; MgCO3↓(white) + Na+}$$

$$\ce{NaHCO3 + Mg^2+ -&gt; MgCO3↓(white) + H2O + CO2 ^}$$

When carbonate salt is reacted with $\ce{MgSO4}$, a white salt precipited while bicarbonate salt on reacting with $\ce{MgSO4}$, not only a white salt precipited but also a brisk effervescence occur. The gas  is detected  by passing it through lime water.