Step-by-step explanation:
We have to find the net ionic equation for the following reaction.
Pb(NO₃)₂ + 2 NaI --> 2 NaNO₃ + PbI₂
First we have to figure out if these compounds are soluble or insoluble. The two reactants are soluble, NaNO₃ is also soluble but PbI₂ is a yellow crystalline solid that is insoluble in water.
Pb(NO₃)₂ (aq) + 2 NaI (aq) ---> 2 NaNO₃ (aq) + PbI₂ (s) molecular equation
Since PbI₂ is a solid and is insoluble, it won't form ions when it is in solution. The other three compounds can form ions. We can get the total ionic equation by separating those compounds into their ions.
Pb²⁺ (aq) + 2 NO₃⁻ (aq) + 2 Na⁺ (aq) + 2 I⁻ (aq) ---> 2 Na⁺ + 2 NO₃⁻ (aq) + PbI₂ (s) total ionic equation
And finally to get the net ionic equation we have to cancel the spectator ions. We have to cancel out the ions that are present on both sides of the equation.
Pb²⁺ (aq) + 2 I⁻ (aq) ---> PbI₂ (s) net ionic equation
Answer: Pb²⁺ (aq) + 2 I⁻ (aq) ---> PbI₂ (s) net ionic equation