Answer: The reactions that will occur are \(2AgNO_3+Ni\rightarrow 2Ag+Ni(NO_3)_2\) and \(Pb+Zn(CH_3COO)_2\rightarrow Zn+Pb(CH_3COO)_2\)
Explanation:
Single displacement reaction is defined as the reaction in which more reactive element displaces a less reactive element from its chemical reaction.
The reactivity of metal is determined by a series known as reactivity series. The metals lying above in the series are more reactive than the metals which lie below in the series.
\(A+BC\rightarrow AC+B\)
On moving down the group, the reactivity of non-metals decreases.
For the given options:
Option 1: \(2NaBr+I_2\rightarrow 2NaI+Br_2\)
As, iodine is less reactive than bromine. It will not be able to displace bromine from its reaction. So the reaction will not occur.
\(2NaBr+I_2\rightarrow \text{No reaction}\)
Option 2: \(2Fe+Al_2O_3\rightarrow 2Al+Fe_2O_3\)
As, iron is less reactive than aluminium. It will not be able to displace aluminium from its reaction. So the reaction will not occur.
\(2Fe+Al_2O_3\rightarrow \text{No reaction}\)
Option 3: \(2AgNO_3+Ni\rightarrow 2Ag+Ni(NO_3)_2\)
As, nickel is more reactive than silver. It will easily displace silver from its reaction. So the reaction will occur.
\(2AgNO_3+Ni\rightarrow 2Ag+Ni(NO_3)_2\)
Option 4: \(Pb+Zn(CH_3COO)_2\rightarrow Zn+Pb(CH_3COO)_2\)
As, lead is more reactive than zinc. It will not be able to displace zinc from its reaction. So the reaction will occur.
\(Pb+Zn(CH_3COO)_2\rightarrow Zn+Pb(CH_3COO)_2\)
Hence, the reactions that will occur are \(2AgNO_3+Ni\rightarrow 2Ag+Ni(NO_3)_2\) and \(Pb+Zn(CH_3COO)_2\rightarrow Zn+Pb(CH_3COO)_2\)
