Write the balanced NET ionic equation for the reaction when strontium chloride and sodium phosphate are mixed in aqueous solution. If no reaction occurs, write only NR.

Question

I am just confused because I don't know where to start? we went over it in class but I still have no idea how to get to the part where we cancel the repeats to get the net ionic equation.

Answer 1

You want to start with the molecular equation:

3SrCl₂ (aq) + 2Na₃PO₄(aq) --> Sr₃(PO₄)₂(s) + 6 NaCl(aq)

In ionic equation you will dissociate aqueous species into ions

3Sr²⁺(aq) + 6Cl^- (aq) + 6Na⁺ (aq) + 2PO₄^3-(aq) --> Sr₃(PO₄)₂(s) + 6Na⁺ (aq) + 6Cl^- (aq)

After crossing out the spectator ions you have a net ionic equation:

3Sr²⁺(aq) + 2PO₄^3-(aq) --> Sr₃(PO₄)₂(s)