Q. During the electrolysis of cryolite, aluminium and fluorine are formed in molar ratio
A) 1:2
B) 2:3
C) 1:1
D) 1:3
Explanation
(b)
Electrolysis of cryolite can be explained as
$\ \ \ \ Na_{3}AlF_{6} \rightleftharpoons 3NaF + AlF_{3}$
$4AlF_{3} \rightleftharpoons 4Al^{3 +} + 12F^{-}$
$\ \ + 12e^{-} \downarrow$ $\downarrow - 12e^{-}$
$4Al$ $6F_{2}$
(at cathode) (at anode)
So, the molar ratio of Al and $F_{2}$ is 4:6=2:3
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.