Question

write symbolic notation and overall reaction of the cell when zinc electrode is coupled with SHE

Answer 1

Answer:

Overall reaction will be:

$2H^{+}(aq)+Zn(s)--->H_{2}(g)+Zn^{+2}(aq)$

The symbolic notation will be:

$Zn/Zn^{+2}(aq)//H^{+}(aq)/H_{2}(g)$

Explanation:

SHE stands for standard hydrogen electrode.

The electrode potential of SHE is considered to be zero.

Any substance with less than this electrode potential (negative) will undergo oxidation when coupled with SHE and any substance with more than this electrode potential (positive) will undergo reduction when coupled with SHE.

The elecrtode potential of Zinc is -0.76 V.

Thus Zinc will undergo oxidation and SHE will undergo reduction.

The reactions will be:

At anode:

$Zn(s)--->Zn^{+2}(aq)+2e$

At cathode:

$H^{+}(aq)+e--->\frac{1}{2}H_{2}(g)$

Overall reaction will be:

$2H^{+}(aq)+Zn(s)--->H_{2}(g)+Zn^{+2}(aq)$

The symbolic notation will be:

$Zn/Zn^{+2}(aq)//H^{+}(aq)/H_{2}(g)$