1. Write the reactants and products:
* Reactants: Zinc nitrate (Zn(NO₃)₂) and sodium phosphate (Na₃PO₄)
* Products: Zinc phosphate (Zn₃(PO₄)₂) and sodium nitrate (NaNO₃)
2. Write the unbalanced equation:
Zn(NO₃)₂ (aq) + Na₃PO₄ (aq) → Zn₃(PO₄)₂ (s) + NaNO₃ (aq)
3. Balance the equation:
* Balance the zinc (Zn) atoms: Put a 3 in front of Zn(NO₃)₂.
* Balance the phosphate (PO₄) groups: Put a 2 in front of Na₃PO₄.
* Balance the sodium (Na) atoms: Put a 6 in front of NaNO₃.
* Balance the nitrate (NO₃) groups: The equation is now balanced with 6 nitrate groups on each side.
The balanced molecular equation is:
3 Zn(NO₃)₂ (aq) + 2 Na₃PO₄ (aq) → Zn₃(PO₄)₂ (s) + 6 NaNO₃ (aq)
Key points:
* The state symbols (aq) and (s) indicate whether the substances are aqueous (dissolved in water) or solid.
* This reaction is a precipitation reaction because zinc phosphate (Zn₃(PO₄)₂) is an insoluble solid that forms a precipitate.
