Question

Which of the following reaction is used to make a fuel cell.

• A. $H_{2}SO_{4}$
• B. $Pb_{(s)} + S{O_{4}^{2 -}}{(aq)} \rightarrow $$$PbSO{4(s)} + 2e^{-}$$
• C. $2SO_{4(aq)}^{2 -} \rightarrow$$$S_{2}O_{8(aq)}^{2 -} + 2e^{-}$$
• D. $2H_{2(g)} + 4O{H^{-}}{(aq)} \rightarrow $$$4H{2}O_{(l)} + 4e^{-}$$

Answer 1

Answer: (C)

$2SO_{4(aq)}^{2 -} \rightarrow$$$S_{2}O_{8(aq)}^{2 -} + 2e^{-}$$

Answer 2

Overall reaction – $2H_{2(g)} + O_{2(g)} \rightarrow 2H_{2}O(l)$.