What is the net ionic equation for this reaction: CaSO4+HCl?

1 Answer

ncchemist's profile pic

ncchemist | eNotes Employee

Posted on

The full chemical equation is:

CaSO4 + 2HCl --> H2SO4 + CaCl2

This states that calcium sulfate plus hydrochloric acid becomes sulfuric acid and calcium chloride.  Calcium sulfate is a solid that does not readily dissolve in water.  Calcium chloride is a solid that is highly soluble in water.  Sulfuric acid and hydrochloric acid are both highly soluble in water.  So the end result is that an insoluble solid (CaSO4) is ultimately dissolved in water using acid.  To get the ionic equation, we need to list each chemical in terms of how it exists in water.  We see this below:

CaSO4(s) + 2H^(+1) + 2Cl^(-1) --> 2H^(+1) + SO4^(-2) + Ca^(+2) + 2Cl^(-1)

We eliminate the spectator ions to get the net ionic equation.  The spectator ions are the ions that are unchanged during the course of the reaction.  The net ionic equation is shown below:

CaSO4 --> Ca^(+2) + SO4^(-2)