What are the spectator ions in the reaction below?

[tex]\[ Mg (s) + Zn^{2+} + 2NO_3^{-} \rightarrow Mg^{2+} + 2NO_3^{-} + Zn (s) \][/tex]

A. [tex]\( Mg (s) \)[/tex] and [tex]\( Zn (s) \)[/tex]

B. [tex]\( Zn^{2+} \)[/tex] and [tex]\( Mg^{2+} \)[/tex]

C. [tex]\( NO_3^{-} \)[/tex], [tex]\( Zn^{2+} \)[/tex], and [tex]\( Mg^{2+} \)[/tex]

D. [tex]\( NO_3^{-} \)[/tex]



Answer :

To determine the spectator ions in the given chemical reaction, it is important to identify the ions or molecules that do not change from the reactants to the products side.

The reaction is:
[tex]\[ Mg (s) + Zn^{2+} + 2NO_3^{-} \rightarrow Mg^{2+} + 2NO_3^{-} + Zn (s) \][/tex]

Step-by-step, let's analyze the components:

1. Start with the reactants and products:
- Reactants: [tex]\( Mg (s) \)[/tex], [tex]\( Zn^{2+} \)[/tex], and [tex]\( 2NO_3^{-} \)[/tex]
- Products: [tex]\( Mg^{2+} \)[/tex], [tex]\( 2NO_3^{-} \)[/tex], and [tex]\( Zn (s) \)[/tex]

2. Identify changes in oxidation states or forms of the species involved:
- [tex]\( Mg (s) \)[/tex] changes to [tex]\( Mg^{2+} \)[/tex]
- [tex]\( Zn^{2+} \)[/tex] changes to [tex]\( Zn (s) \)[/tex]

3. Determine which species remain unchanged:
- The [tex]\( NO_3^{-} \)[/tex] ion appears as [tex]\( 2NO_3^{-} \)[/tex] on both sides of the equation, indicating that it has not undergone any change and has remained constant throughout the reaction.

4. Conclusion:
- The ion [tex]\( NO_3^{-} \)[/tex] does not participate in the chemical reaction and remains unchanged. Therefore, it is the spectator ion.

Thus, the spectator ion in this reaction is indeed [tex]\( NO_3^{-} \)[/tex]. Therefore, the correct answer is:

D. [tex]\( NO_3^{-} \)[/tex]