Electrolytic reduction of alumina to aluminum by the Hall-Heroult process is carried out

Options

A. in the presence of cryolin which forms a melt at hight temprature process is carride out
B. In the presents of `NaCI`
C. In the presence of thaorite
D. in the presence of cryyolte which a mell at lower temprature and increases the electrical conductivity.

Answer

d

Explanation

Fused aluminum `(Al_(2)O_(3))` is a had conductor of electricity .Therefore crystable `(NaAIF_(2))` and flotspar `(CaF_(2))~ are added is perified `AI_(2)O_(3)` which not only make stamone a good conductor of electricity but also reduce the melting point of the rain to around `1140 K`
The processof obtaiting AI by electrodrsis of a mixture of paralified `AI_(2)O_(3) and NaAIF_(2) ` called half and hevoids process