[NewCandle] Measuring Half-Cell Charge

[Frederick Sparber]

A Half-Cell refresher from Wiki.

Lots of choices for the electrolyte surrounded by the electrode rather
than the opposite.

" A half cell is a structure that contains a conductive electrode and
a surrounding conductive electrolyte separated by a
naturally-occurring Helmholtz double layer. Chemical reactions within
this layer momentarily pump electric charges between the electrode and
the electrolyte, resulting in a potential difference between the
electrode and the electrolyte. The typical reaction involves a metal
atom in the electrode being dissolved and transported as a positive
ion across the double layer, causing the electrolyte to acquire a net
positive charge while the electrode acquires a net negative charge.
The growing potential difference creates an intense electric field
within the double layer, and the potential rises in value until the
field halts the net charge-pumping reactions."

"A standard half cell, used in electrochemistry, consists of a metal
electrode in a 1 molar aqueous solution of the metal's salt, at 298
Kelvin (25o Celsius). The electrochemical series, which consists of
standard electrode potentials and is closely related to the reactivity
series, was generated by measuring the between the metal half cell in
a circuit with a standard hydrogen half cell, connected by a salt
bridge."

Fred

On 9/11/07, Frederick Sparber <fsparber at gmail.com> wrote:
> Hi Keith and Nick.
>
> I will get back to repeating the pendulum experiment when my able
> assistant is available, but I strongly recommend a short key-chain
> laser pointer (about 2.5 inches long) that range in price from $5.00
> and up, attached to the bottom of the float.
>
> Shining it on a quadrille tablet or such would help too.
>
> Fred
>