For chemistry, I'm a little confused...

Question

You know how you work out the solubilities substances from the solubility table, right? Well by mixing sodium carbonate with hydrochloric acid will produce sodium chloride and hydrogen carbonate...

Na2CO3 (aq) 2HCl (aq) -----> 2NaCl (aq) H2CO3 (s)

and from this eq which i worked out by myself and referring to the solubility table shows that it would produce aqueous sodium chloride and a precipitate of hydrogen carbonate. Well, from this my friend said that its wrong coz hydrogen carbonate is a soluble substance so it can't precipitate. Even though im pretty sure that im right (or at least i hope i am, coz she's the smartest girl in class)

So the question is am i reading the solubility table wrong or is she wrong? If either of us is wrong, it would be great if someone could explain it to us.

thnx :)

Answer 1

You are both right.

Your solubility table probably says "all carbonates are insoluble except for those of the alkaline metals" or something like that.  The people who wrote that table were not smart enough to think of hydrogen carbonate as a possibility.

Hydrogen carbonate is soluble, so it doesn't precipitate, but it does decompose:

H2CO3 --> H2O plus CO2

Which is why carbonates fizz when you add acid to them.