What are the spectator ions in Mg(s) + Zn^(2+) + 2NO_3^(-) -> Mg^(2+) + 2NO_3^(-) + Zn(s)Mg(s)+Zn2++2NO−3→Mg2++2NO−3+Zn(s)?
1 Answer
The nitrate anions,
Explanation:
A spectator ion is an ion that is present on both sides of a chemical equation.
In other words, in order for an ion to be a spectator ion, it must exist as such as a reactant and as a product in the balanced chemical equation.
You're dealing with a single replacement reaction in which magnesium metal,
The products of this reaction are zinc metal,
The problem provides you with the complete ionic equation for this reaction
"Mg"_ ((s)) + "Zn"_ ((aq))^(2+) + 2"NO"_ (3(aq))^(-) -> "Mg"_ ((aq))^(2+) + 2"NO"_ (3(aq))^(-) + "Zn"_ ((s))Mg(s)+Zn2+(aq)+2NO−3(aq)→Mg2+(aq)+2NO−3(aq)+Zn(s)
As you can see, the reactants' side contains two ions
- the zinc cation,
"Zn"^(2+)Zn2+ - the nitrate anion,
"NO"_3^(2-)NO2−3
Likewise, the product's side also contains two ions
- the magnesium cation,
"Mg"^(2+)Mg2+ - the nitrate anion,
"NO"_3^(-)NO−3
Because the nitrate anions are present on both sides of the equation, they are spectator ions.
This means that you can eliminate them from the complete ionic equation
"Mg"_ ((s)) + "Zn"_ ((aq))^(2+) + color(red)(cancel(color(black)(2"NO"_ (3(aq))^(-)))) -> "Mg"_ ((aq))^(2+) + color(red)(cancel(color(black)(2"NO"_ (3(aq))^(-)))) + "Zn"_ ((s))
to get the net ionic equation
"Mg"_ ((s)) + "Zn"_ ((aq))^(2+) -> "Mg"_ ((aq))^(2+) + "Zn"_ ((s))