Question

Metals posses varying reduction potentials. Iron can reduce Cu+2 (aq) to copper metal. Silver can reduce Au+ (aq) to gold metal. Sodium can reduce Fe3+(aq) to iron metal and copper can reduce Ag+(aq) to silver metal. Which of the following statements is true?copper can reduce Na+ (aq) to sodium metalIron can reduce Au+(aq) to gold metalsilver can reduce Fe3+(aq) to ironnone of the above statements is true

Answer 1

Answer: The true statement is iron can reduce $Au^+(aq)$ to gold metal

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.

$A+BC\rightarrow AC+B$

Metal A is more reactive than metal B.

We are given:

Iron can reduce copper, silver can reduce gold, sodium can reduce iron and copper can reduce silver metal.

The increasing order of reactivity thus follows:

$Au$

where, sodium is most reactive and gold is least reactive

For the given options:

Option 1:  Copper cannot easily reduce sodium ion to sodium metal because it is less reactive.

$Cu(s)+Na^+(aq.)\rightarrow \text{ No reaction}$

Option 2:  Iron cant easily reduce gold ion to gold metal because it is more reactive.

$Fe(s)+3Au^+(aq.)\rightarrow Fe^{3+}(aq.)+3Au(s)$

Option 3:  Silver cannot easily reduce iron ion to iron metal because it is less reactive.

$Ag(s)+Fe^{3+}(aq.)\rightarrow \text{ No reaction}$

Hence, the true statement is iron can reduce $Au^+(aq)$ to gold metal