Question
Explain standard hydrogen electrode. (SHE)
✓
Answer
→ Standard Hydrogen Electrode works as a reference electrode for other half cells.
→ The standard hydrogen electrode consists of a platinum electrode coated with platinum black. The electrode is dipped in an acidic solution and pure hydrogen gas bubbled through it.
→ The concentration of both the reduced and oxidised forms of hydrogen is maintained at unity.
→ This implies that the pressure of hydrogen gas is one bar and the concentration of hydrogen ion in the solution is one molar.
→ When this half cell connected to other half cells, To form a complete all, The SHE can acts as as cathode or anode
→ If it acts as cathode the following reduction reaction takes place on the platinum strip
$H ^{+}( aq )(1 M )+ e ^{-} \rightleftharpoons \frac{1}{2} H _2(g, 1 bar )$
→ If it acts as anode the oxidation reaction takes places on the anode
$\frac{1}{2} H _2(g, 1$ bar $) \rightleftharpoons H ^{+}( aq , 1 M )+ e ^{-}$
→ Electrode potential of Standard Hydrogen gas Electrode is accepted zero at all temperature.
→ The standard hydrogen electrode consists of a platinum electrode coated with platinum black. The electrode is dipped in an acidic solution and pure hydrogen gas bubbled through it.
→ The concentration of both the reduced and oxidised forms of hydrogen is maintained at unity.
→ This implies that the pressure of hydrogen gas is one bar and the concentration of hydrogen ion in the solution is one molar.
→ When this half cell connected to other half cells, To form a complete all, The SHE can acts as as cathode or anode
→ If it acts as cathode the following reduction reaction takes place on the platinum strip
$H ^{+}( aq )(1 M )+ e ^{-} \rightleftharpoons \frac{1}{2} H _2(g, 1 bar )$
→ If it acts as anode the oxidation reaction takes places on the anode
$\frac{1}{2} H _2(g, 1$ bar $) \rightleftharpoons H ^{+}( aq , 1 M )+ e ^{-}$
→ Electrode potential of Standard Hydrogen gas Electrode is accepted zero at all temperature.
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