Question

The standard reduction potentials for $Cu ^{2+} / Cu ; Zn ^{2+} / Zn$; $Li ^{+} / Li ; Ag ^{+} / Ag$ and $H ^{+} / H _{2}$ are $+0.34 \,V ,-0.762\, V, -3.05\, V ,+0.80 \,V$ and $0.00\, V$ respectively. Choose the strongest reducing agent among the following

• A. $Zn$
• B. $H _{2}$
• C. $Ag$
• D. $Li$

Answer 1

Answer: (D)

More the negative reduction potential, more is the tendency to lose electron. The reducing power increases as the standard reduction potential becomes more and more negative.
Thus, $Li$ is the strongest reducing agent as the standard reduction potential of $Li ^{+} / Li$ is most negative, $-3.05\, V$.