Question

complete the balanced molecular chemical equation for the reaction below.
if no reaction occurs, write nr after the reaction arrow. be sure to include the proper phases for all species within the reaction.
cr₂(so₄)₃(aq) + (nh₄)₂co₃(aq) →

Explanation:

Step1: Predict the products

This is a double - displacement reaction. In a double - displacement reaction \(AB + CD\to AD+CB\).
For \(Cr_2(SO_4)_3(aq)+(NH_4)_2CO_3(aq)\), the products will be \(Cr_2(CO_3)_3\) and \((NH_4)_2SO_4\).
The general form of the reaction before balancing is \(Cr_2(SO_4)_3(aq)+(NH_4)_2CO_3(aq)\to Cr_2(CO_3)_3 + (NH_4)_2SO_4\)

Step2: Balance the sulfate and carbonate ions

The sulfate \((SO_4^{2 -})\) and carbonate \((CO_3^{2 -})\) ions are polyatomic ions.
Looking at the sulfate ions: there are \(3\) \(SO_4^{2 -}\) ions in \(Cr_2(SO_4)_3\). So we need \(3\) moles of \((NH_4)_2SO_4\) to balance the sulfate ions.
Looking at the carbonate ions: there are \(3\) \(CO_3^{2 -}\) ions in \(Cr_2(CO_3)_3\). So we need \(3\) moles of \((NH_4)_2CO_3\) to balance the carbonate ions.
Looking at the ammonium \((NH_4^{+})\) and chromium \((Cr^{3+})\) ions: The balanced equation is \(Cr_2(SO_4)_3(aq)+3(NH_4)_2CO_3(aq)\to Cr_2(CO_3)_3(s)+3(NH_4)_2SO_4(aq)\)

Step3: Determine the phase of \(Cr_2(CO_3)_3\)

According to solubility rules, most carbonates are insoluble except those of group 1 (alkali metals) and ammonium. Since \(Cr\) is not an alkali metal, \(Cr_2(CO_3)_3\) is insoluble and has the phase \((s)\) (solid)

Answer:

\(Cr_2(SO_4)_3(aq)+3(NH_4)_2CO_3(aq)\to Cr_2(CO_3)_3(s)+3(NH_4)_2SO_4(aq)\)