Question

Which ions are spectator ions in the formation of a precipitate of agcl via combining aqueous solutions of cocl2 and agno3?

Answer 1

AgNO3 reacts with CoCl2 based on the following equation:
AgNO3 + CoCl2 ........> CoNO3 + AgCl2

The complete ionic equation for this reaction is:
Co2+(aq) + 2Cl- (aq) + 2Ag+(aq) + 2NO3-(aq) ...> 2AgCl(s) + Co2+(aq) + 2NO3-(aq) 
while the net ionic equation is:
Cl-(aq) + Ag+(aq) → AgCl(s)

From this ionic equations, we can see that Co2+ and NO3- remained unchanged in the ionic equations. Therefore Co2+ and NO3- are the spectator ions.