Answer :
(a) The net ionic equation will be,
![2Cr^{2+}(aq)+3CO_3^{2-}(aq)\rightarrow Cr_2(CO_3)_3(s)](https://tex.z-dn.net/?f=2Cr%5E%7B2%2B%7D%28aq%29%2B3CO_3%5E%7B2-%7D%28aq%29%5Crightarrow%20Cr_2%28CO_3%29_3%28s%29)
The spectator ions are, ![NH_4^{+}\text{ and }SO_4^{2-}](https://tex.z-dn.net/?f=NH_4%5E%7B%2B%7D%5Ctext%7B%20and%20%7DSO_4%5E%7B2-%7D)
(b) The net ionic equation will be,
![Ba^{2+}(aq)+SO_4^{2-}(aq)\rightarrow BaSO_4(s)](https://tex.z-dn.net/?f=Ba%5E%7B2%2B%7D%28aq%29%2BSO_4%5E%7B2-%7D%28aq%29%5Crightarrow%20BaSO_4%28s%29)
The spectator ions are, ![K^{+}\text{ and }NO_3^{-}](https://tex.z-dn.net/?f=K%5E%7B%2B%7D%5Ctext%7B%20and%20%7DNO_3%5E%7B-%7D)
(c) The net ionic equation will be,
![Fe^{2+}(aq)+2OH^{-}(aq)\rightarrow Fe(OH)_2(s)](https://tex.z-dn.net/?f=Fe%5E%7B2%2B%7D%28aq%29%2B2OH%5E%7B-%7D%28aq%29%5Crightarrow%20Fe%28OH%29_2%28s%29)
The spectator ions are, ![K^{+}\text{ and }NO_3^{-}](https://tex.z-dn.net/?f=K%5E%7B%2B%7D%5Ctext%7B%20and%20%7DNO_3%5E%7B-%7D)
Explanation :
In the net ionic equations, we are not include the spectator ions in the equations.
Spectator ions : The ions present on reactant and product side which do not participate in a reactions. The same ions present on both the sides.
(a) The given balanced ionic equation will be,
![Cr_2(SO_4)_3(aq)+3(NH_4)_2CO_3(aq)\rightarrow 3(NH_4)_2SO_4(aq)+Cr_2(CO_3)_3(s)](https://tex.z-dn.net/?f=Cr_2%28SO_4%29_3%28aq%29%2B3%28NH_4%29_2CO_3%28aq%29%5Crightarrow%203%28NH_4%29_2SO_4%28aq%29%2BCr_2%28CO_3%29_3%28s%29)
The ionic equation in separated aqueous solution will be,
![2Cr^{2+}(aq)+3SO_4^{2-}(aq)+6NH_4^{+}(aq)+3CO_3^{2-}(aq)\rightarrow Cr_2(CO_3)_3(s)+6NH_4^{+}(aq)+3SO_4^{2-}(aq)](https://tex.z-dn.net/?f=2Cr%5E%7B2%2B%7D%28aq%29%2B3SO_4%5E%7B2-%7D%28aq%29%2B6NH_4%5E%7B%2B%7D%28aq%29%2B3CO_3%5E%7B2-%7D%28aq%29%5Crightarrow%20Cr_2%28CO_3%29_3%28s%29%2B6NH_4%5E%7B%2B%7D%28aq%29%2B3SO_4%5E%7B2-%7D%28aq%29)
In this equation,
are the spectator ions.
By removing the spectator ions from the balanced ionic equation, we get the net ionic equation.
The net ionic equation will be,
![2Cr^{2+}(aq)+3CO_3^{2-}(aq)\rightarrow Cr_2(CO_3)_3(s)](https://tex.z-dn.net/?f=2Cr%5E%7B2%2B%7D%28aq%29%2B3CO_3%5E%7B2-%7D%28aq%29%5Crightarrow%20Cr_2%28CO_3%29_3%28s%29)
(b) The given balanced ionic equation will be,
![Ba(NO_3)_2(aq)+K_2SO_4(aq)\rightarrow 2KNO_3(aq)+BaSO_4(s)](https://tex.z-dn.net/?f=Ba%28NO_3%29_2%28aq%29%2BK_2SO_4%28aq%29%5Crightarrow%202KNO_3%28aq%29%2BBaSO_4%28s%29)
The ionic equation in separated aqueous solution will be,
![Ba^{2+}(aq)+2NO_3^{-}(aq)+2K^{+}(aq)+SO_4^{2-}(aq)\rightarrow BaSO_4(s)+2K^{+}(aq)+2NO_3^{-}(aq)](https://tex.z-dn.net/?f=Ba%5E%7B2%2B%7D%28aq%29%2B2NO_3%5E%7B-%7D%28aq%29%2B2K%5E%7B%2B%7D%28aq%29%2BSO_4%5E%7B2-%7D%28aq%29%5Crightarrow%20BaSO_4%28s%29%2B2K%5E%7B%2B%7D%28aq%29%2B2NO_3%5E%7B-%7D%28aq%29)
In this equation,
are the spectator ions.
By removing the spectator ions from the balanced ionic equation, we get the net ionic equation.
The net ionic equation will be,
![Ba^{2+}(aq)+SO_4^{2-}(aq)\rightarrow BaSO_4(s)](https://tex.z-dn.net/?f=Ba%5E%7B2%2B%7D%28aq%29%2BSO_4%5E%7B2-%7D%28aq%29%5Crightarrow%20BaSO_4%28s%29)
(c) The given balanced ionic equation will be,
![Fe(NO_3)_2(aq)+2KOH(aq)\rightarrow 2KNO_3(aq)+Fe(OH)_2(s)](https://tex.z-dn.net/?f=Fe%28NO_3%29_2%28aq%29%2B2KOH%28aq%29%5Crightarrow%202KNO_3%28aq%29%2BFe%28OH%29_2%28s%29)
The ionic equation in separated aqueous solution will be,
![Fe^{2+}(aq)+2NO_3^{-}(aq)+2K^{+}(aq)+2OH^{-}(aq)\rightarrow Fe(OH)_2(s)+2K^{+}(aq)+2NO_3^{-}(aq)](https://tex.z-dn.net/?f=Fe%5E%7B2%2B%7D%28aq%29%2B2NO_3%5E%7B-%7D%28aq%29%2B2K%5E%7B%2B%7D%28aq%29%2B2OH%5E%7B-%7D%28aq%29%5Crightarrow%20Fe%28OH%29_2%28s%29%2B2K%5E%7B%2B%7D%28aq%29%2B2NO_3%5E%7B-%7D%28aq%29)
In this equation,
are the spectator ions.
By removing the spectator ions from the balanced ionic equation, we get the net ionic equation.
The net ionic equation will be,
![Fe^{2+}(aq)+2OH^{-}(aq)\rightarrow Fe(OH)_2(s)](https://tex.z-dn.net/?f=Fe%5E%7B2%2B%7D%28aq%29%2B2OH%5E%7B-%7D%28aq%29%5Crightarrow%20Fe%28OH%29_2%28s%29)