The standard reduction potentials are provided\ $\mathrm{E}^{\circ} \mathrm{Zn}^{2+} / \mathrm{Zn}=

Question

The standard reduction potentials are provided\ $\mathrm{E}^{\circ} \mathrm{Zn}^{2+} / \mathrm{Zn}=-0.76 \mathrm{~V}$\ $\mathrm{E}^{\circ} \mathrm{Cu}^{2+} / \mathrm{Cu}=+0.34 \mathrm{~V}$\ $\mathrm{E}^{\mathrm{o}} \mathrm{Ag}^{+} / \mathrm{Ag}=+0.80 \mathrm{~V}$\ $\mathrm{E}^{\mathrm{o}} \mathrm{Ni}^{2+} / \mathrm{Ni}=-0.25 \mathrm{~V}$\ Which of the following reactions will provide maximum voltage\

Professor PC Thomas Classes · Answer

$\quad \mathrm{E}_{	ext {cell }}=\mathrm{E}_{	ext {cathode }}^{-\mathrm{O}}-\mathrm{E}_{	ext {anode }}^{\mathrm{O}}$ Max emf is obtained when the red.pot of the anode is the minimum and red pot. Of cathode is maximum.Answer is C $\mathrm{E}_{	ext {cell }}=\mathrm{E}_{\mathrm{Ag}}^{\mathrm{o}}-\mathrm{E}_{\mathrm{Zn}}^{\mathrm{o}}=0.80-(-0.76)=+1.56 \mathrm{~V}$\