Question

A galvanic (voltaic) cell consists of an electrode composed of magnesium in a 1.0 M1.0 M magnesium ion solution and another electrode composed of gold in a 1.0 M1.0 M gold(III) ion solution, connected by a salt bridge. Calculate the standard potential for this cell at 25 °C.25 °C.

Answer 1

+ 3.87 V

Step-by-step explanation:

Data provided in the question:

The galvanic (voltaic) cell is composed of 1.0 M magnesium ion solution and 1.0 M gold(III) ion solution

Now,

The standard potential for this cell at 25°C ,

E₀ =
`E_{\textup{Anode}}-E_{\textup{Cathode}}`

i.e

E₀ =
`E_(Au^(3+)/Au)-E_{\textup{Mg^(2+)/Mg}}`

also,

from the standard reduction potential table

Mg²⁺ (aq) + 2e⁻ ⇒ Mg (s) E = -2.71 V

Au³⁺ (aq) + 3 e⁻ ⇒ Au (s) E = +1.50 V

Therefore,

E₀ = 1.50 - ( -2.37 )

or

E₀ = + 3.87 V