Question

In the chemical reaction, CaCl2+Na2Co3 yields CaCo3 + NaCl why does Co3 still keep the subscript of 3 even though when you crossed the positive 2 and negative two charges they canceled each other out?

Answer 1

It is a reaction of exchange. CO₃ is an ion. Noneof its components changes its charge. So CO₃ still has thesubscript of 3.