Calculate Δ G o for the following cell reaction Zn s + Ag 2 O s + H 2 O l → Zn 2 + aq + 2 Ag s + 2 OH − aq E…

Calculate Δ G o for the following cell reaction Zn s + Ag 2 O s + H 2 O l Zn 2 + aq + 2 Ag s + 2 OH aq
E A g + / A g 0 = + 0.80 V   a n d   E Z n + 2 / Z n 0 = - 0.76 V ,F=96500
(Given:  K sp of AgOH = 2 × 10 8 )
  1. - 305 k J / m o l
  2. 212   k J / m o l
  3. 305 k J / m o l
  4. 301 k J / m o l

Solution

Calculation for E O H - A g 2 O A g -

Reduction [ 2 A g + + 2 e - 2 A g s , G 1 o = - 2 × F × E o A g + | A g

Ionisation [ A g 2 O + H 2 O l 2 A g + + 2 O H - G 2 o = - 2.303 R T l o g k s p 2

Net A g 2 O + H 2 O l + 2 e - 2 A g s + 2 O H - , G 3 o = - 2 × F × E O H - A g 2 O A g o
G 3 o = G 1 o + G 2 o
+ 2 × F × E O H - A g 2 O A g o = + 2 × F × E o A g + | A g + 2.303 R T l o g k s p 2 2 F
E O H - A g 2 O A g o = E o A g + | A g + 0.06 2 × 2 log k s p
= 0.8 + 0.06 log 2 × 10 - 8
= 0.8 + 0.06 - 8 + 0.3
= 0.8 + 0.06 × - 7.7
= 0.8 - 0.462
= 0.338 V o l t 0.34 V G o = - n F E c e u o
= - n F E c o - E A R e d
= - 2 × E O H - A g 2 O A g o - E Z n + 2 | Z n o
= - 2 × 96500 × 0.34 + 0.76
= - 2 × 96500 × 1.1 v o l t
= 212300 J
= 212.3  k J

Asked in: JEE-TOPICTESTS-CHEMISTRY

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