Two electrochemical cells are assembled in which the following reactions occur-V2-aq-VO2-aq-2H-aq-2V3-aq-H2Ol- Ecell0-0-616 VV3-aq-Ag-aq-H2Ol- VO2-aq-2H-aq-Ags- Ecell0-0-439 VCalculate the E0 for the half-cell reaction-V3-aq-e- V2-aq Given - EAg-aq-Ags0-0-799 V

The number of electrons involoved in each reaction V^2+(aq)+VO^2+(aq)+2H^+(aq)→2V^3+(aq)+H_2O(l)........(1); Δ G^0_1 = F × 0.616 V^3+(aq)+Ag^+(aq)+H_2O(l) ...

You visited us 1 times! Enjoying our articles? Unlock Full Access!

Byju's Answer

Standard VII

Chemistry

EMF

Two electroch...

Question

Two electrochemical cells are assembled in which the following reactions occur.

$V^{2 +} (a q) + V O^{2 +} (a q) + 2 H^{+} (a q) \to 2 V^{3 +} (a q) + H_{2} O (l); E_{c e l l}^{0} = 0.616 V$

$V^{3 +} (a q) + A g^{+} (a q) + H_{2} O (l) \to V O^{2 +} (a q) + 2 H^{+} (a q) + A g (s); E_{c e l l}^{0} = 0.439 V$

Calculate the $E^{0}$ for the half-cell reaction,
$V^{3 +} (a q) + e \to V^{2 +} (a q)$
Given :
$(E_{A g^{+} (a q) / A g (s)}^{0} = 0.799 V)$

- 1.055 V

No worries! We‘ve got your back. Try BYJU‘S free classes today!

+ 1.055 V

No worries! We‘ve got your back. Try BYJU‘S free classes today!

- 0.563 V

No worries! We‘ve got your back. Try BYJU‘S free classes today!

- 0.256 V

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

Open in App

Solution

The correct option is D $- 0.256 V$
The number of electrons involoved in each reaction

$V^{2 +} (a q) + V O^{2 +} (a q) + 2 H^{+} (a q) \to 2 V^{3 +} (a q) + H_{2} O (l) . . . . . . . . (1);$
$Δ G_{1}^{0} = - F \times 0.616$

$V^{3 +} (a q) + A g^{+} (a q) + H_{2} O (l) \to V O^{2 +} (a q) + 2 H^{+} (a q) + A g (s) . . . . . . (2);$
$Δ G_{2}^{0} = - F \times 0.439$
Adding (1) and (2), we get,
$V^{2 +} (a q) + A g^{+} (a q) \to V^{3 +} (a q) + A g (s) . . . . . . . (3)$

$Δ G_{3}^{0} = - (1 \times F \times 0.616 + 1 \times F \times 0.439$
$Δ G_{3}^{0} = - 1.055 F$

$∴$ $E_{c e l l}^{0} = - \frac{Δ G_{3}}{n F} = \frac{1.055 F}{F} = 1.055 V .$

Further, for the above cell,

$V^{2 +} (a q) + A g^{+} (a q) \to V^{3 +} (a q) + A g (s)$

$E_{c e l l}^{0} = E_{A g^{+} (a q) / A g (s)}^{0} - E_{V^{3 +} (a q) / V^{2 +} (a q)}^{0}$

$1.055 = 0.799 - E_{V^{3 +} (a q) / V^{2 +} (a q)}^{0}$

$E_{V^{3 +} (a q) / V^{2 +} (a q)}^{0} = 0.799 - 1.055$
$E_{V^{3 +} (a q) / V^{2 +} (a q)}^{0} = - 0.256 V$

Suggest Corrections

Similar questions

Δ G^{o}

of the cell reaction

A g C l (s) + 1 / 2 H_{2} (g) \to A g (s) + H^{+} (a q .) + {C l}^{-} (a q)

- 21.52 k J

Calculate the EMF for the cell reaction:

2 A g C l (c) + H_{2} (g) \to A g (s) + 2 H^{+} (a q .) + 2 {C l}^{-} (a q .)

Q. You are given the following reduction reactions and

E^{\circ}

values:

F e^{3 +} (a q) + e^{-} \to F e^{2 +} (a q) E^{\circ} = + 0.771 V

F e^{2 +} (a q) + 2 e^{-} \to F e (s) E^{\circ} = - 0.447 V

Calculate

E^{\circ}

for the half-cell reaction

F e^{3 +} (a q) + 3 e^{-} \to F e (s)

Q. Two electrochemical cells are assembled in which following reactions occur.

V^{2 +} + V O^{2 +} + 2 H^{+} \to 2 V^{3 +} + H_{2} O; E_{c e l l}^{o} = 0.616 V

V^{3 +} + A g + 2 H_{2} O \to V O_{2} + 4 H^{+} + A g (s); E_{c e l l}^{o} = 0.439 V

E^{o}

for half reaction,

V^{3 +} + e \to V^{2 +}

is :
Given that

E_{A g^{+} / A g} = 0.799 V .

Q. Consider a spontaneous electrochemical cell between

C u

and

A l

. Predict what would happen if excess concentrated

N a O H

were added to the cell with copper ions and a precipitate forms.

Standard Potential (V)	Reduction Half-Reaction
$2.87$	$F_{2} (g) + 2 e^{-} \to 2 F^{-} (a q)$
$1.51$	$M n O_{4}^{-} (a q) + 8 H^{+} (a q) + 5 e^{-} \to M n^{2 +} (a q) + 4 H_{2} O (l)$
$1.36$	$C l_{2} (a q) + 3 e^{-} \to 2 C l^{-} (a q)$
$1.33$	$C r_{2} O_{7}^{2 -} (a q) + 14 H^{+} (a q) + 6 e^{-} \to 2 C r^{3 +} (a q) + 7 H_{2} O (l)$
$1.23$	$O_{2} (g) + 4 H^{+} (a q) + 4 e^{-} \to 2 H_{2} O (l)$
$1.06$	$B r_{2} (l) + 2 e^{-} \to 2 B r^{-} (a q)$
$0.96$	$N O_{3}^{-} (a q) + 4 H^{+} (a q) + 3 e^{-} \to N O (g) + H_{2} O (l)$
$0.80$	$A g^{+} (a q) + e^{-} \to A g (s)$ $
$0.77$	$F e^{3 +} (a q) + e^{-} \to F e^{2 +} (a q)$
$0.68$	$O_{2} (g) + 2 H^{+} (a q) + 2 e^{-} \to H_{2} O_{2} (a q)$
$0.59$	$M n O_{4}^{-} (a q) + 2 H_{2} O (l) + 3 e^{-} \to M n O_{2} (s) + 4 O H^{-} (a q)$
$0.54$	$I_{2} (s) + 2 e^{-} \to 2 I^{-} (a q)$
$0.40$	$O_{2} (g) + 2 H_{2} O (l) + 4 e^{-} \to 4 O H^{-} (a q)$
$0.34$	$C u^{2 +} (a q) + 2 e^{-} \to C u (s)$
$0$	$2 H^{+} (a q) + 2 e^{-} \to H_{2} (g)$
$- 0.28$	$N i^{2 +} (a q) + 2 e^{-} \to N i (s)$
$- 0.44$	$F e^{2 +} (a q) + 2 e^{-} \to F e (s)$
$- 0.76$	$Z n^{2 +} (a q) + 2 e^{-} \to Z n (s)$
$- 0.83$	$2 H_{2} O (l) + 2 e^{-} \to H_{2} (g) + 2 O H^{-} (a q)$
$1.66$	$A l^{3 +} (a q) + 3 e^{-} \to A l (s)$
$- 2.71$	$N a^{+} (a q) + e^{-} \to N a (s)$
$- 3.05$	$L i^{+} (a q) + e^{-} \to L i (s)$

Q. Consider a galvanic cell using solid

C u

and

F e

metals with their corresponding solutions.
What is the

E_{c e l l}^{\circ}

Standard Potential (V)	Reduction Half-Reaction
$2.87$	$F_{2} (g) + 2 e^{-} \to 2 F^{-} (a q)$
$1.51$	$M n O_{4}^{-} (a q) + 8 H^{+} (a q) + 5 e^{-} \to M n^{2 +} (a q) + 4 H_{2} O (l)$
$1.36$	$C l_{2} (a q) + 3 e^{-} \to 2 C l^{-} (a q)$
$1.33$	$C r_{2} O_{7}^{2 -} (a q) + 14 H^{+} (a q) + 6 e^{-} \to 2 C r^{3 +} (a q) + 7 H_{2} O (l)$
$1.23$	$O_{2} (g) + 4 H^{+} (a q) + 4 e^{-} \to 2 H_{2} O (l)$
$1.06$	$B r_{2} (l) + 2 e^{-} \to 2 B r^{-} (a q)$
$0.96$	$N O_{3}^{-} (a q) + 4 H^{+} (a q) + 3 e^{-} \to N O (g) + H_{2} O (l)$
$0.80$	$A g^{+} (a q) + e^{-} \to A g (s)$ $
$0.77$	$F e^{3 +} (a q) + e^{-} \to F e^{2 +} (a q)$
$0.68$	$O_{2} (g) + 2 H^{+} (a q) + 2 e^{-} \to H_{2} O_{2} (a q)$
$0.59$	$M n O_{4}^{-} (a q) + 2 H_{2} O (l) + 3 e^{-} \to M n O_{2} (s) + 4 O H^{-} (a q)$
$0.54$	$I_{2} (s) + 2 e^{-} \to 2 I^{-} (a q)$
$0.40$	$O_{2} (g) + 2 H_{2} O (l) + 4 e^{-} \to 4 O H^{-} (a q)$
$0.34$	$C u^{2 +} (a q) + 2 e^{-} \to C u (s)$
$0$	$2 H^{+} (a q) + 2 e^{-} \to H_{2} (g)$
$- 0.28$	$N i^{2 +} (a q) + 2 e^{-} \to N i (s)$
$- 0.44$	$F e^{2 +} (a q) + 2 e^{-} \to F e (s)$
$- 0.76$	$Z n^{2 +} (a q) + 2 e^{-} \to Z n (s)$
$- 0.83$	$2 H_{2} O (l) + 2 e^{-} \to H_{2} (g) + 2 O H^{-} (a q)$
$1.66$	$A l^{3 +} (a q) + 3 e^{-} \to A l (s)$
$- 2.71$	$N a^{+} (a q) + e^{-} \to N a (s)$
$- 3.05$	$L i^{+} (a q) + e^{-} \to L i (s)$

Join BYJU'S Learning Program

Explore more

EMF

Standard VII Chemistry

Join BYJU'S Learning Program