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Electrochemical Series

Given E Ag ...

Question

Given $E_{A g^{+} / A g}^{0}$ = +0.80 V ; $E_{C u^{2 +} / C u}^{0}$ = +0.34 V ;
$E_{F e {3 +}^{+} / F e 2 +}^{0}$ = +0.76V ;
$E_{C e {4 +}^{+} / C e 3 +}^{0}$ = + 1.60 V
Which of the following statements is not correct ?

F e^{3 +}

does not oxidise

C e^{3 +}

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Cu reduces

A g^{+}

to Ag

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Ag will reduces

C u^{2 +}

to Cu

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F e^{2 +}

reduces

C u^{2 +}

to Cu

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Solution

The correct option is B Ag will reduces $C u^{2 +}$ to Cu
Reduction potential is given as:
$E_{A g^{+} / A g}^{0}$ = +0.80 V ; $E_{C u^{2 +} / C u}^{0}$ = +0.34 V, $E_{F e^{3 +} / F e^{2 +}}^{0}$ = +0.76V; $E_{C e^{4 +} / C e^{3 +}}^{0}$ = + 1.60 V
Thus the increasing order of reduction potential is:
$C u^{2 +} < F e^{3 +} < A g^{+} < C e^{4 +}$
possible reactions are:
$C u + M^{n +} \to C u^{2 +} + M$ where $M^{n +} = F e^{3 +}, A g^{+}, C e^{4 +}$
$F e + M^{n +} \to F e^{2 +} + M$ where $M^{n +} = A g^{+}, C e^{4 +}$
thus higher the reduction potential more the tendency to get reduced.
A. $F e$ reduces $C e^{4 +}$ to $C e^{3 +}$ and itself gets oxidised to $F e^{2 +}$ but does not oxidise $C e^{3 +}$ .
B. Cu metal can reduce $F e^{3 +}, A g^{+}, C e^{4 +}$ ions into Fe, Ag and Ce, respectively.
C. Ag will not reduce $C u^{2 +}$ to Cu as its reduction tendency is higher than $C u^{2 +}$
D. $F e^{2 +}$ can reduce $C u^{2 +}$ to Cu as the oxidation potential of $E_{F e^{2 +} / F e^{3 +}}^{0}$ =-0.76 V is higher than $E_{C u / C u^{2 +}}^{0}$ =-0.34 V.

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Similar questions

A g^{+}

C u^{2 +}

The standard reducation potentials of

$Z n^{2 +} | Z n, C u^{2 +} | C u$ and $A g^{+} | A g$

are respectively -0.76, 0.34 and 0.8 V. The following cells were constructed.

a) $Z n | Z n^{2 +} | | C u^{2 +} | C u$

b) $Z n | Z n^{2 +} | | A g^{+} | A g$

c) $C u | C u^{2 +} | | A g^{+} | A g$

What is the correct order $E {^{0}}_{c e l l}$ of these cells?

Δ G^{o}

C u^{2 +} + F e \to F e^{2 +} + C u

E_{C u^{2 +} | C u}^{o} = + 0.34

E_{F e^{2 +} | F e}^{o} = - 0.44

2 A g^{+} + C u ⟶ 2 A g + C u^{2 +}

E_{{C u}^{2 +} / C u}

E_{{A g}^{+} / A g}

(E^{0} values : F e^{3 +} ∣ F e^{2 +} = + 0.77 V; I_{2} (s) ∣ I^{-} = + 0.54 V; C u^{2 +} | C u = + 0.34 V; A g^{+} ∣ A g = + 0.80 V)

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