Question

The reaction $\frac{1}{2}{H}_2\left(g\right)+AgCl\left(aq\right)\to H^{+}\left(aq\right)+Ag\left(s\right)$ can be represented in the galvanic cell as:

• A.
  $Pt\left(s\right)|H_2\left(g\right)||H^{+}\left(aq\right)|AgCl\left(aq\right)||Ag\left(s\right)$
• B.
  
  $Pt\left(s\right)|H^{+}\left(aq\right)|H_2\left(g\right)||AgCl\left(aq\right)|Ag\left(s\right)$
• C.
  $Pt\left(s\right)|H_2\left(g\right)|H^{+}\left(aq\right)||AgCl\left(aq\right)|Ag\left(s\right)$
• D. $AgCl\left(aq\right)|Ag\left(s\right)||H_2\left(g\right)|H^{+}\left(aq\right)|Pt\left(s\right)$

Answer 1

The correct option is C

$Pt\left(s\right)|H_2\left(g\right)|H^{+}\left(aq\right)||AgCl\left(aq\right)|Ag\left(s\right)$
In the given reaction,
$H_2$ gets oxidised to $H^{+}$ in galvanic cell and $A{g}^{+}$ get reduced to Ag.

In galvanic cell, oxidation occurs at anode half cell and reduction occurs at cathode half cell.

Rules for Cell representation:
1. Anode half cell should be on left side and cathode half cell should be on right side.

2. Separation of two phase should be shown by vertical line $(\mid )$. This line indicates phase boundary.

3. If various material present in the same phase, it should be shown together with commas (,).

4. The salt bridge is represented by double slash $(\mid \mid )$ between the two half cells.

5. The significant features of the substance like pressure of a gas, concentration of ions, etc. should be indicated in brackets immediately after writing the substance.

$Pt\left(s\right)|H_2\left(g\right)|H^{+}\left(aq\right)$ forms anode half cell

$AgCl\left(aq\right)|Ag\left(s\right)$ forms cathode half cell

$\therefore$ The cell representation can be written as

$Pt\left(s\right)|H_2\left(g\right)|H^{+}\left(aq\right)||AgCl\left(aq\right)|Ag\left(s\right)$

Hence, the correct option is C