An element A forms an oxide A2O5.
(a) What is the valency of element A?
(b) What will be the formula of chloride of A?
(a) Let the valency of element A be y, then 2y + 5(-2) = 0
So, y = valency of element A = 5
(b) As valency of element A is 5 and valency of chlorine is -1,
So, the formula of chloride of A is ACl5.