Question

Given that $E°$ values of $Ag^{+}/Ag, K^{+}/K, Mg^{2+}/Mg$ and $Cr^{3+}/Cr$ are $0.80 V, -2.93 V, -2.37 V$ and $-0.74 V$ respectively. Therefore the order for the reducing power of the metal is

• A. $Ag > Cr > Mg > K$
• B. $Ag < Cr < Mg < K$
• C. $Ag > Cr > K > Mg$
• D. $Cr > Ag > Mg > K$

Answer 1

Answer: (B)

More the negative $E^{°}$ value, larger the reducing power of the metal The greater the standard reduction potential, the greater tendency to reducing power of metal. $K$ has greater value $(-2.93)$ so $K > Mg > Cr > Ag$