# Question #cde21

Feb 7, 2017

It's arbitrary. We could have set it to be $\text{1.752452352 V}$, but we felt like $\text{0.000 V}$ was a nicer number. I'm not kidding.

There are other reference electrodes, a common one being the saturated calomel electrode (SCE):

$\text{Hg"_2^(2+)(aq) + 2e^(-) rightleftharpoons 2"Hg} \left(l\right)$

In reference to that, all reduction potentials will differ; its reduction potential is $\text{0.2444 V}$ relative to the standard hydrogen electrode (SHE).

If we use the SCE as a reference, we decrease numbers previously relative to the SHE by $\text{0.2444 V}$. For instance, a potential relative to SHE of $\text{1.7000 V}$ would become $\text{1.4556 V}$ when relative to the SCE.