Question

What is the net ionic equation for:

1) Barium sulfate + nitric acid

2) Calcium phosphate + nitric acid

3) Silver acetate + nitric acid

I got these for the answers but were marked wrong. The teacher crossed out what was wrong in each, not sure what I did incorrect, though.

1) BaSO4(s) -> Ba^2+(aq) + SO4^2-(aq) (both products crossed out)

2) Ca3(PO4)2(s) -> 3Ca^2+(aq) + 2PO4^3-(aq) (2PO4^3-(aq) crossed out)

3) AgC2H3O2(s) -> Ag+(aq) + C2H3O2^-(aq) (acetate in products crossed out)

Thank you!

Answer 1

1) Barium sulfate + nitric acid
BaSO₄ (s) + HNO₃ (aq) ------> Ba(NO₃)₂ (aq) + H₂SO₄ (aq)
balance the equation after writing the equation,
  BaSO₄ (s) + 2 HNO₃ (aq) ------> Ba(NO₃)₂ (aq) + H₂SO₄ (aq)
write in ionic form
BaSO₄ (s) +2H⁺(aq)+2NO₃^-(aq) -----> Ba²⁺(aq)+2NO₃^-(aq)+2H⁺(aq)+SO₄^2-(aq)
cancel out the spectator ions i.e) 2H⁺, 2NO₃^-
So the net ionic equation will be,
BaSO₄ (s) --------> Ba²⁺(aq) + SO₄^2-(aq)

2) Calcium phosphate + nitric acid
Ca₃(PO₄)₂ (s) + 6 HNO₃ (aq) -----> 3 Ca(NO₃)₂ (aq) + 2 H₃PO₄ (aq)
Ca₃(PO₄)₂ (s)+6H⁺(aq)+6NO₃^-(aq) ---> 3Ca²⁺(aq)+6NO₃^-(aq)+6H⁺(aq)+2PO₄^-(aq)
canceling the common ions on both sides i.e) spectator ions like 6H⁺, 6NO₃^-
Ca₃(PO₄)₂ (s) ---------> 3Ca²⁺(aq) + 2PO₄^-(aq) is the final net ionic equation.

3) CH₃CO₂Ag(s) + HNO₃ (aq) ------> AgNO₃(aq) + CH₃COOH(aq)
  CH₃CO₂Ag(s)+H⁺(aq)+NO₃^-(aq) ----> Ag⁺(aq)+NO₃^-(aq)+CH₃COO^-(aq)+H⁺(aq)
The final net ionic equation you will get after canceling spectator ions on both sides,
CH₃CO₂Ag(s) ------> Ag⁺(aq) + CH₃COO^-(aq)