Question 4.6: Writing Equations for Reactions For each of the following re...
Writing Equations for Reactions
For each of the following reactions, write the molecular equation, the complete ionic equation, and the net ionic equation.
a. Aqueous potassium chloride is added to aqueous silver nitrate to form a silver chloride precipitate plus aqueous potassium nitrate.
b. Aqueous potassium hydroxide is mixed with aqueous iron(III) nitrate to form a precipitate of iron(III) hydroxide and aqueous potassium nitrate.
a. Molecular:
KCl(aq) + AgN O _{3} (aq) → AgCl(s) + KN O _{3} (aq)
Complete ionic (remember that any ionic compound dissolved in water will be present as the separated ions):
K^{+} (aq) + Cl^{-} (aq) + Ag^{+} (aq) + N O _{3} ^{-} (aq) →
↑ ↑
Spectator ion Spectator ion
AgCl(s) + K^{+} (aq) + N O _{3} ^{-} (aq)
↑ ↑ ↑
Solid, Spectator Spectator
not ion ion
written
as separate ions
Net ionic: Canceling the spectator ions,
\cancel{ K^{+}}(aq) + Cl^{-} (aq) + Ag^{+} (aq) + \cancel{N O _{3} ^{-}} (aq) → AgCl(s) + \cancel{ K^{+}}(aq) + \cancel{N O _{3} ^{-}} (aq)
gives the following net ionic equation:
Cl^{-} (aq) + Ag^{+} (aq) → AgCl(s)
b. Molecular:
3KOH(aq) + Fe(N O_{3})_{3} (aq) → Fe(OH)_{3} (s) + 3 KN O_{3} (aq)
Complete ionic:
3 K^{+}(aq) + 3 OH ^{-}(aq) + Fe^{3+} (aq) + 3 N O_{3} ^{-}(aq) → Fe(OH)_{3} (s) + 3 K^{+}(aq) + 3 N O_{3} ^{-}(aq)
Net ionic:
3 OH ^{-}(aq) + Fe^{3+} (aq) → Fe(OH)_{3} (s)