When HCl reacts with Na2CO3, what is created? More specifically, what are the crystals that remain?

The questions that I need to answer:
4) What is the shape of the crystals of the product?
5) Have you seen crystals like these before, where?

I wasn't able to see the result of my experiment, because I was absent the following class.

1 answer

The products are NaCl and H2CO3, which turns into CO2 and H2O. See if you can figure out the other answers.