Which of the following cell is concentration cell ?

Options

A. `Cu_((S))|Cu_((aq,1M))^(2+)||Cu_((aq,1M))^(2+)|Cu_((S))`
B. `Zn_((S))|Zn_((aq,0.5M))^(2+)||Cu_((aq,0.1M))^(2+)|Cu_((S))`
C. `Cu_((S))|Cu_((aq,0.5M))^(2+)||Cu_((aq,0.5M))^(2+)||Cu_((S))`
D. `""^(Theta)Pt|H_(2_((g,1" bar")))|HCl_((aq,0.002M))||HCl_((aq,0.005M))|H_(2_((g,1" bar")))|Pt^(o+)`

Answer

D

Explanation

`""^(Theta)Pt|H_(2_((g,1" bar")))|HCl_((aq,0.002M))||HCl_((aq,0.005M))|H_(2_((g,1" bar")))|Pt^(o+)`