To determine which substances will appear in the equilibrium constant expression for the given reaction
[tex]\[
2 Ag ^{+}(a q)+Z n(s) \leftrightarrow Z n^{2+}(a q)+2 Ag (s)
\][/tex]
we need to follow a few rules:
1. Only include aqueous solutions (aq) and gases (g) in the equilibrium constant expression.
2. Exclude solids (s) and liquids (l) from the equilibrium constant expression.
Let's examine each species in the reaction:
- [tex]\( Ag^{+}(aq) \)[/tex]: This is an aqueous ion and should be included in the equilibrium constant expression.
- [tex]\( Zn(s) \)[/tex]: This is a solid and should not be included.
- [tex]\( Zn^{2+}(aq) \)[/tex]: This is an aqueous ion and should be included in the equilibrium constant expression.
- [tex]\( Ag(s) \)[/tex]: This is a solid and should not be included.
By applying these rules, the substances that will appear in the equilibrium constant expression are:
[tex]\[
Ag^{+} \quad \text{and} \quad Zn^{2+}
\][/tex]
Thus, the correct answer is:
- [tex]\( Ag^{+} \)[/tex]
- [tex]\( Zn^{2+} \)[/tex]
