Answer:
2AgI + 1Na₂S ⟶ 1Ag₂S +2NaI
Explanation:
silver(I) iodide + sodium sulfide ⟶ silver(I) sulfide + sodium iodide
1. Convert the word equation to a chemical equation:
AgI + Na₂S ⟶ Ag₂S + NaI
2. Put a 1 in front of the most complicated-looking formula (Na₂S?):
AgI + 1Na₂S ⟶ Ag₂S + NaI
3. Balance Na:
We have fixed 2 Na on the left. We need 2 Na on the right. Put a 2 in front of NaI.
AgI + 1Na₂S ⟶ Ag₂S +2NaI
4. Balance S:
We have fixed 1 S on the left. We need 1 O on the right. Put a 1 in front of Ag₂S.
AgI + 1Na₂S ⟶ 1Ag₂S +2NaI
5. Balance Ag:
We have fixed 2Ag on the right. We need 2 Ag on the left. Put a 2 in front of AgI.
2AgI + 1Na₂S ⟶ 1Ag₂S +2NaI
Every formula now has a coefficient. The equation should be balanced.
6. Check that atoms balance:
Atom On the left On the right
Ag 2 2
I 2 2
Na 2 2
S 1 1
The balanced equation is
2AgI + 1Na₂S ⟶ 1Ag₂S +2NaI