I'm in Gen Chem and this question in the online homework program is stumping me.
"Many homeowners treat their lawns with CaCO3(s) to reduce the acidity of the soil. Write a net ionic equation for the reaction of CaCO3(s) with a strong acid."
The hints when I get it wrong are:
"If calcium carbonate reacts with acid, carbonic acid will form, which decomposes into water and carbon dioxide, the ultimate neutralization products of this reaction.
Does CaCO3(s) appear as an ionic species in the ionic equation?
Will the anion of the acid appear in the net ionic equation?
Did you write the net ionic equation, rather than the molecular equation or the overall ionic equation?"
My best guess for the total ionic equation, if I pick HCl as the strong acid, is
2H[+](aq)+2Cl[-](aq)+CaCO3(s) -> H2O(l)+CO2(g)+Ca[2+](aq)+2Cl[-](aq)
Brackets added for a modicum of clarity
Cross off the 2Cl[-](aq) to make it into a net ionic equation and we get... a wrong answer. Help?