To determine which of the given equations represent precipitation reactions, we need to check whether a precipitate (an insoluble solid) is formed in the reaction. If there is an insoluble product, the reaction is a precipitation reaction.
1. Equation 1:
[tex]\[ Na_2S + FeBr_2 \rightarrow 2 NaBr + FeS \][/tex]
Sodium bromide (NaBr) is soluble, but iron sulfide (FeS) is insoluble in water, forming a precipitate.
- Conclusion: This is a precipitation reaction.
2. Equation 2:
[tex]\[ MgSO_4 + CaCl_2 \rightarrow MgCl_2 + CaSO_4 \][/tex]
Magnesium chloride (MgCl_2) is soluble, while calcium sulfate (CaSO_4) is only slightly soluble and is commonly considered to form a precipitate in this context.
- Conclusion: This is a precipitation reaction.
3. Equation 3:
[tex]\[ LiOH + NH_4I \rightarrow LiI + NH_4OH \][/tex]
Both lithium iodide (LiI) and ammonium hydroxide (NH_4OH) are soluble in water.
- Conclusion: This is not a precipitation reaction.
4. Equation 4:
[tex]\[ 2 NaCl + K_2S \rightarrow Na_2S + 2 KCl \][/tex]
Both sodium sulfide (Na_2S) and potassium chloride (KCl) are soluble in water.
- Conclusion: This is not a precipitation reaction.
5. Equation 5:
[tex]\[ AgNO_3 + NaCl \rightarrow AgCl + NaNO_3 \][/tex]
Sodium nitrate (NaNO_3) is soluble, but silver chloride (AgCl) is insoluble in water, forming a precipitate.
- Conclusion: This is a precipitation reaction.
Based on these conclusions, the correct equations that represent precipitation reactions are:
1. [tex]\( Na_2S + FeBr_2 \rightarrow 2 NaBr + FeS \)[/tex]
2. [tex]\( MgSO_4 + CaCl_2 \rightarrow MgCl_2 + CaSO_4 \)[/tex]
5. [tex]\( AgNO_3 + NaCl \rightarrow AgCl + NaNO_3 \)[/tex]
These correspond to the numerical indices provided:
[tex]\[ \boxed{0, 1, 4} \][/tex]
Thus, the equations that represent precipitation reactions are the first, second, and fifth equations.
