Question

Write an equation for the action of heat on aluminium hydroxide.

Answer 1

Alumina has a very high melting point (> ${2000}^{0}C$ ). Cryolite lowers the fusion temperature from ${2000}^{0}C$ to ${1000}^{0}C$ and enhances conductivity. The positively charged aluminium ions $A{l}^{3+}$ are attracted to the cathode (negative electrode). The aluminium ions accept electrons from the cathode and get reduced to form aluminium atoms (or aluminium metal).