Standard hydrogen electrode and cu notation

The standard hydrogen electrode (SHE) is the reference electrode whose potential is taken as exactly 0.00 V at all temperatures. It consists of a platinum foil coated with platinum black, dipped in 1 M H⁺ solution (1 M HCl) with pure hydrogen gas bubbled at 1 atm pressure and 25°C.

Electrode notation: Pt, H₂ (1 atm) | H⁺ (1 M)

Cell notation of the Cu electrode with SHE: Pt, H₂ (1 atm) | H⁺ (1 M) || Cu²⁺ (1 M) | Cu

Here SHE is the anode and Cu is the cathode.

• Anode: H₂ → 2H⁺ + 2e⁻
• Cathode: Cu²⁺ + 2e⁻ → Cu
• Cell reaction: H₂ + Cu²⁺ → 2H⁺ + Cu

The measured emf (+0.34 V) is the standard reduction potential of Cu: E°(Cu²⁺/Cu) = +0.34 V.