Question

What is the net ionic equation for the reaction of sodium carbonate with zinc nitrate?

I know that the answer is: CO3(2-) (aq) + Zn(2+) (aq) --> ZnCO3(s) but could you explain why it is not Na2CO3 (aq) + Zn(NO3)2(aq) --> 2NaNO3(aq) + ZnCO3(s)? And how did CO3(2-) (aq) + Zn(2+) (aq) --> ZnCO3(s) come from Na2CO3 (aq) + Zn(NO3)2(aq) --> 2NaNO3(aq) + ZnCO3(s)?

Thank you.

Answer 1

net ionic equations show only those ions reacting, ignore those that are spectator ions so

Na2CO3 + Zn(NO3)2 = ZnCO3 + 2NaNO3

note that in solution, in ionic :

2Na+(aq) + CO3-2(aq) + Zn+2(aq) + 2NO3-(aq) = ZnCO3(s) + 2Na+(aq) + 2NO3-(aq)

note that you need to eliminate all spectator ions (ions that show in the left and right)

so

2Na+(aq) + CO3-2(aq) + Zn+2(aq) + 2NO3-(aq) = ZnCO3(s) + 2Na+(aq) + 2NO3-(aq)

cancle bold marked ions

CO3-2(aq) + Zn+2(aq)= ZnCO3(s)

which was your answer