Question

A gas 'X' at $1atm$ is bubbled through a solution containing a mixture of $1M$ 'Y' and $1M$ 'Z' at ${25}^{o}C.$
If the standard reduction potentials of X,Y,Z follows the order:
$Z>Y>X$
then choose the correct statement:

• A. Y will oxidise X and not Z
• B. Y will oxidise Z and not X
• C. Y will oxidise both X and Z
• D. Y will reduce both X and Z

Answer 1

The correct option is A Y will oxidise X and not Z

Standard reduction potentials (SRP) of the half cell electrodes are calculated and arranged in a series of increasing order which is known as electrochemical series.
The standard electrode potential of $H^{+}/H_2$ couple is zero.

Here, a negative $E^0$ signifies that it has high tendency to get oxidised and the redox couple is a stronger reducing agent than the $H^{+}/H_2$ couple.

A positive $E^0$ signifies that it has high tendency to get reduced and the redox couple is a stronger oxidising agent than the $H^{+}/H_2$ couple.

Going down the electrochemical series, the $E^0$ value decrease i.e., the strength of oxidising agent gets reduced.
Here, standard reduction potential decrease in order
$Z>Y>X$
Hence, Z is the strongest oxidising agent.
'Y' is stronger oxidising agent than 'X'.
Hence, 'Y' can oxidise 'X' and not 'Z'.