Agalvanic cell consists of a ni2+/ ni half-cell and a standard hydrogen electrode. if the ni2+/ ni half-cell standard cell functions as the anode, and the standard cell potential is 0.26 v, what is the standard reduction potential for the ni2+/ ni half-cell?

You are given a galvanic cell consists of a Ni²⁺/ Ni half-cell and a standard hydrogen electrode. Also, you are given that the half cell Ni²⁺/ Ni will act as an anode, and the standard cell potential is 0.26V. You are asked to find the standard reduction potential for the half cell Ni²⁺/ Ni.

You will have a half - reaction for both nickel and hydrogen
The conversion of the symbol Ni²⁺/ Ni half-cell is 
Ni²⁺ + 2e⁻ → Ni (s) E = 0.26V
and the conversion of the standard hydrogen electrode (SHE) is
2H⁺ + 2e⁻ → H₂ (g) E = 0V

Since H⁺ ions is a it difficult to set up during the process, nickel will be deposited at the cathode side instead of the anode. Therefore, The standard electron potential of the nickel will have -0.26V. 

The answer to that would be magnesium