Question

What is the reaction takes place at the cathode in the standard hydrogen electrode?

• A. $Pt\to P{t}^{+}+e^{-}$
• B. $P{t}^{+}+e^{-}\to Pt$
• C. $H_2\to 2H^{+}+2e^{-}$
• D. $2H^{+}+2e^{-}\to H_2$

Answer 1

The correct option is D $2H^{+}+2e^{-}\to H_2$

In standard hydrogen electrode (SHE), $H_2$ gas oxidizes at anode
As $H_2\to 2H^{+}+2e^{-}$
And $H^{+}$ ions reduce at cathode as
$H^{+}+2e^{-}\to H_2$