In: Chemistry
Calculate ΔG° for the following reaction as written
Ni2+ (aq) + Sn (s) → Ni (s) + Sn2+ (aq)
given the following reduction half-reactions and standard reduction potentials.
Sn2+ (aq) + 2 e- → Sn (s) E° = -0.15V
Ni2+ (aq) + 2 e- → Ni (s) E° = -0.25V
anode reaction: oxidation takes place
Sn(s) -------------------------> Sn+2 (aq) + 2e- , E0Sn+2/Sn = - 0.15 V
cathode reaction : reduction takes palce
Ni+2(aq) + 2e- -----------------------------> Ni(s) , E0Ni+2/Ni = -0.25V
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net reaction: Ni2+ (aq) + Sn (s) → Ni (s) + Sn2+ (aq)
E0cell= E0cathode- E0anode
E0cell= E0Ni+2/Ni - E0Sn+2/Sn
= -0.25 - (-0.15)
= -0.10 V
detla G0 = -nF Ecell0
= - 2x 96, 485 x (-0.10)
= 19297 J
= 19.3 kJ
ΔG° = 19.3 kJ