Question

in a given solution of AgNO3. which one of the following can not displace Ag from AgNO3 solution. ? Mg, zn,Au and Cu.

Answer 1

Au(gold) because it is less reactive than all other elements in above list

Answer 2

Answer: The correct answer is Au (gold).

Explanation:

A single displacement reaction is defined as the reaction in which a more reactive metal displaces a less reactive metal from its chemical reaction. The reactivity is determined on the basis of reactivity series. The metals which lie above in the series are more reactive than the ones which lie below in the series.

The metals given are Magnesium (Mg), Zinc (Zn), Gold (Au) and Copper (Cu)

The reaction of these metals with silver is given by the reactivity series. The metals which lie above in the series of Silver are Magnesium, Zinc and Gold. Thus, these metals will easily replace silver from its reaction.

Gold lie below in the series, thus will not replace silver from its reaction.

$Mg+2AgNO_3\rightarrow Mg(NO_3)_2+2Ag\\Zn+2AgNO_3\rightarrow Zn(NO_3)_2+Ag\\Au+AgNO_3\rightarrow \text{No reaction}\\Cu+2AgNO_3\rightarrow Cu(NO_3)_2+2Ag$

Hence, the correct answer is Au (gold).