Question

question 4 (2 points)
which answer shows a balanced reaction for the following description:
solutions of sodium carbonate & silver nitrate react to form a silver carbonate precipitate & aqueous sodium nitrate
○naco₃ (aq) + agno₃ (aq) → agco₃ (s) + nano₃
○na₂co₃ (aq) + 2 agno₃ (aq) → ag₂co₃ (s) + 2 nano₃
○na₂co₃ (aq) + agno₃ (aq) → ag₂co₃ (s) + nano₃
○na₂co₃ + 2 agno₃ → ag₂co₃ + 2 nano₃

Explanation:

Step1: Write correct chemical formulas

Sodium carbonate is $Na_2CO_3$, silver nitrate is $AgNO_3$, silver carbonate is $Ag_2CO_3$ and sodium nitrate is $NaNO_3$. The reaction occurs in aqueous solution so we write (aq) for aqueous substances and (s) for precipitate.

Step2: Balance the reaction

We need to balance the number of atoms on both sides of the equation. For sodium ($Na$), silver ($Ag$), nitrogen ($N$) and oxygen ($O$) atoms. Starting with the un - balanced reaction $Na_2CO_3(aq)+AgNO_3(aq)
ightarrow Ag_2CO_3(s)+NaNO_3(aq)$. We see that we need 2 moles of $AgNO_3$ to get 2 moles of silver on the product side and 2 moles of $NaNO_3$ to balance the sodium and nitrate ions. The balanced reaction is $Na_2CO_3(aq)+2AgNO_3(aq)
ightarrow Ag_2CO_3(s)+2NaNO_3(aq)$.

Answer:

$Na_2CO_3(aq)+2AgNO_3(aq)
ightarrow Ag_2CO_3(s)+2NaNO_3(aq)$