Question

The mass of aluminium liberated by 1 faraday

Answer 1

The equation of aluminum electrolysis is

$$\text{Al}^{3+}+3\bar{e}\rightarrow \text{Al}^0.$$

Therefore, 1 mole of aluminum requires 3 moles of electrons. Keep in mind that 1 faraday is not a SI unit and equals 96485.33 Coulombs, however, this unit is easier to use. According to the reaction, in the equation below $z=3$:

$$m=F\frac{M}{z}=1\cdot\frac{27\text{ g}}{3}=9\text{ g}.$$