Ok so basically you take an Ionic table and see if the charges for each compound cancel each other out. If they dont, add a subscript so the negative and positive charges cancel each other out. Then check of there is the same number of molecules on each side of the equation. i.e. nacl + cu-> cucl2 +na
On the product side there is 2 more chlorine than on the reactant side. so you would put a number in from of each compound until there is the same number of every molecule on all sides. i.e. 2nacl + cu -> 2na+ cucl2
