Question

E^Θ values of some redox couples are given below. On the basis of these values.

E^Θ values: \[\ce{Br2 /Br- = + 1.90; Ag+ / Ag(s) = + 0.80}\];

\[\ce{Cu^{2+} / Cu(s) = + 0.34; I2(s) / I- = 0.54}\]

Options

• \[\ce{Cu}\] will reduce \[\ce{Br-}\]

• \[\ce{Cu}\] will reduce \[\ce{Ag}\]

• \[\ce{Cu}\] will reduce \[\ce{I-}\]

• \[\ce{Cu}\] will reduce \[\ce{Br2}\]

Answer 1

\[\ce{Cu}\] will reduce \[\ce{Br2}\]

Explanation:

Reduction potential is defined as the tendency of the specie to get reduced. More positive the value of E^Θ, greater is the tendency of the species to get reduced and stronger is the oxidising agent. 

On the basis of the given E^Θ values, the order of getting reduced is: 

\[\ce{Br2Ag+I2Cu^{2+}}\]

Hence, \[\ce{Cu}\] has the least tendency to get reduced and will itself gets oxidise and reduce other species as: \[\ce{Br2, Ag+}\] and \[\ce{I2}\].