Question

What is the net ionic equation for the reaction of Ca(NO3)2 and Na2SO4?

Answer 1

Lets start with a rule that ionic compounds do not break apart (there are some instances, but not going to worry about that now)....but the Sodium and Calcium do break from ionic compounds.

Ca(NO3)2 + Na2SO4 combined is a double replacement reaction. Therefore Calcium grabs the Sulfate and Sodium grabs the nitrate.

Calcium has a charge of 2+ and Sulfate has a charge of 2- therefore making CaSO4
Sodium has a charge of 1+ and Nitrate has a charge of 1- therefore making NaNO3

Molecular : Ca(NO3)2 + Na(SO4) ------> Ca(SO4) + Na(NO3) -----This is not balanced

Now list the compounds individually with their charges...remembering that Ionic compounds stay together.

Total Ionic : Ca(2+) + 2NO3 (1-) + Na(2-) + SO4(2+) ----> Ca(2+) + SO4(2-) + Na (1+) + NO3(1-) -----Not balanced

Now cancel out what is on both sides and you end up with your net ionic. This has has to be done after you balance the equations.