To determine the missing reactant in the given neutralization reaction
[tex]\[ \text{______} + KCl \rightarrow AgCl + KNO_3 \][/tex]
we need to examine the products and reactants involved.
1. Identify the products:
- The reaction products are AgCl and KNO_3.
2. Derive the components needed for the reaction:
- AgCl: This product indicates the presence of silver (Ag) and chloride (Cl).
- KNO_3: This product indicates the presence of potassium (K), nitrogen (N), and oxygen (O), specifically in the nitrate form (NO_3).
3. Balance the reaction:
- The reactant KCl provides the potassium (K) and chlorine (Cl) needed for the products.
- Therefore, the missing reactant must provide the silver (Ag) and the nitrate ion (NO_3).
4. Identify the correct reactant from the options:
- Option A: NHO_3: This compound is not a valid chemical formula and does not provide silver (Ag).
- Option B: Ag_2KN: This compound is not a common or valid chemical formula for a neutralization reaction involving these products.
- Option C: AgNO_3: This compound consists of silver (Ag) and nitrate (NO_3), which are exactly the components we need to complete the reaction.
- Option D: KN_2O: This compound is not a valid compound that fits the reaction requirements.
Considering these steps, the only correct reactant that completes the equation is:
[tex]\[ \boxed{\text{C. } AgNO_3} \][/tex]
