Which of the following reaction is preferred at anode during the electrolysis of H 2 SO 4 at higher concentration?

Question

Which of the following reaction is preferred at anode during the electrolysis of H 2 SO 4 at higher concentration? (A) 2 H 2 O (l) longrightarrow O 2(g)+4 H +(a q)+4 e- (B) 2 SO 42-(a q) longrightarrow S 2 O 32-(a q)+2 e- (C) Both (a) and (b) (D) None of these

Tardigrade Admin · Accepted Answer

During the electrolysis of H 2 SO 4 (dilute) 2 H 2 O (l) longrightarrow O 2(g)+4 H +(a q)+4 e- ; E text cell °=1.23 V During the electrolysis of conc. H 2 SO 4 2 SO 42-(a q) longrightarrow S 2 O 82-(a q)+2 e- ; E text cell °=1.96 V

Q. Which of the following reaction is preferred at anode during the electrolysis of $H_{2} S O_{4}$ at higher concentration?

$2 H_{2} O (l) ⟶ O_{2} (g) + 4 H^{+} (a q) + 4 e^{-}$

$2 S O_{4}^{2 -} (a q) ⟶ S_{2} O_{3}^{2 -} (a q) + 2 e^{-}$

Both (a) and (b)

None of these

During the electrolysis of $H_{2} S O_{4}$ (dilute)
$2 H_{2} O (l) ⟶ O_{2} (g) + 4 H^{+} (a q) + 4 e^{-}; E_{cell}^{\circ} = 1.23 V$
During the electrolysis of conc. $H_{2} S O_{4}$
$2 S O_{4}^{2 -} (a q) ⟶ S_{2} O_{8}^{2 -} (a q) + 2 e^{-}; E_{cell}^{\circ} = 1.96 V$

Q. Which of the following reaction is preferred at anode during the electrolysis of H2​SO4​ at higher concentration?

2H2​O(l)⟶O2​(g)+4H+(aq)+4e−

2SO42−​(aq)⟶S2​O32−​(aq)+2e−