Answer: [tex]2AgNO3+Ni\rightarrow Ni(NO_3)_2+2Ag[/tex]
A single replacement reaction is one in which a more reactive element displaces a less reactive element from its salt solution.
1) [tex]2NaBr+I_2\rightarrow 2NaI+Br_2[/tex]
As iodine is less reactive than bromine, it will not be able to displace bromine from its salt solution, hence no reaction will occur.
2)[tex]2Fe+Al_2O_3\rightarrow 2Al+Fe_2O_3[/tex]
As iron lies lower in reactivity series, it is less reactive than Aluminium. It will not be able to displace aluminium from its salt and hence no reaction occur.
3) [tex]2AgNO3+Ni\rightarrow Ni(NO_3)_2+2Ag[/tex]
As nickel lies above in reactivity series, it is more reactive than silver. It will be able to displace silver from its salt and hence reaction will occur.
4) [tex]Pb+Zn(C_2H_3O_2)_2\rightarrow Zn+Pb(C_2H_3O_2)_2[/tex]
As lead lies lower in reactivity series, it is less reactive than zinc. It will not be able to displace zinc from its salt and hence no reaction occur.
