Difference between Sodium Bicarbonate and Sodium Carbonate reacting with HCl In lab, we performed the Solvay process where we had to produce sodium carbonate as the final product. There is a certain step where we put something in the oven and after this, we expect that the product is sodium bicarbonate ($\ce{NaHCO3}$). This product does not get named in the instructions; it is simply referred to as "dry product". After this step, we were asked to add 2 drops of $\ce{HCl}$ to a small amount of the dry product in a watch glass. Finally, we should repeat the watch glass step using $\ce{NaHCO3}$ and $\ce{Na2CO3}$.

After doing these 3 experiments, I observed the same thing (bubbles). I think that the reactions were:

$$\ce{NaHCO3 + HCl -&gt; NaCl +  CO2 + H2O}$$

and for the third one (since I added $\ce{HCl}$ drop-wise to $\ce{Na2CO3}$, $\ce{Na2CO3}$ was in excess):

$$\ce{Na2CO3 + HCl -&gt; NaHCO3 + NaCl}$$   

and then:

$$\ce{Na2CO3 + HCl -&gt; NaCl + CO2 + H2O}$$

I believe the purpose of the 3 experiments was to identify that the dry product was $\ce{NaHCO3}$, but after adding $\ce{HCl}$, I observed exactly the same thing (bubbles) for both known reagents. So I'm confused as to what should be my answer.
It seems to me that the purpose of the 3 experiments with the HCl was not to identify the dry product. You can just write the reactions you observed, that was probably the point.