Chemistry - Electrochemistry Question with Solution | TestHub

More negative the value of standard reduction potential, higher is the reduction power. i.e. Reducing power $\propto \frac{1}{\text{ standard reduction potential }}$ Thus, the correct decreasing order of reducing power of the metal is $$\begin{array}{rl}& \begin{array}{llll}\mathrm{K}& >& \mathrm{Al}& >\end{array}\\ & \left({\mathrm{E}}_{{\mathrm{K}}^{+}/\mathrm{K}}^0=-2.93\mathrm{V}\right)\left({\mathrm{E}}_{{\mathrm{Al}}^{3+}/\mathrm{Al}}^0=-1.66\mathrm{V}\right)\\ & \mathrm{Cr}>\mathrm{Ag}\\ & \left({\mathrm{E}}_{{\mathrm{Cr}}^{3+}/\mathrm{Cr}}^0=-0.74\mathrm{V}\right)\left({\mathrm{E}}_{{\mathrm{Ag}}^{+}}^0/\mathrm{Ag}=0.80\mathrm{V}\right)\\ & \end{array}$$