Ncert Exercises & Solutions

The positive value of the standard electrode potential of Cu²⁺ / Cu indicates that-

a. This redox couple is a stronger reducing agent than the H⁺ /H₂ couple

b. This redox couple is a stronger oxidising agent than H⁺ /H₂

c. Cu can displace H₂ from acid.

d. Cu cannot displace H₂ from acid.

1. (a, b)
2. (b, c)
3. (c, d)
4. (b, d)

"Lesser the E⁰ value of redox couple higher the reducing power”

\begin{array}{l} {Cu}^{2 +} + 2 e^{-} ⟶ Cu & E ° = 0.34 V \\ 2 H^{+} + 2 e^{-} ⟶ H_{2} & E ° = 0.00 V \end{array}

Since, 2H⁺ /H₂ has lesser SRP than Cu²⁺ /Cu redox couple. Therefore,

(i) This redox couple is a stronger oxidizing agent than H⁺ /H₂

(ii) Cu can’t displace H₂ from acid.

Hence, (b) and (d) are correct.