Question

Calculate the value of ΔG that can be obtained from the following cell at 298K.

`(Al)/(Al3+) (0.01M) || (Sn^(2+) (0.015M))/(Sn)`

`E^\circ (Al^(3+))/(Al) = -1.66 V;  E^\circ (Sn^(2+))/(Sn) = -0.14 V`

Answer 1

`(Al)/(Al3+) (0.01M) || (Sn^(2+) (0.015M))/(Sn)`

Given, `E^\circ (Al^(3+))/(Al) = -1.66 V`

           `E^\circ (Sn^(2+))/(Sn) = -0.14`

`Delta G = -"nF""E"_"cell"^\circ`

Where,

n = 3 moles of electrons

F = 96485 C/mol

`E_"cell"^\circ` = 1.52 V

Convert volts to joules per mole:

1 V=1 J/C

Now, Calculate ΔG:

ΔG = −(3 × 96485 C/mol) × (1.52 J/C)

ΔG = −(3 × 96485 × 1.52) J/mol

ΔG = − 440079.8 J/mol

∴ ΔG = − 871742 Joules