The chemical formula of an oxide of an element is a2o5 state the valency of a also write the chemical formula of its chloride

a) Valency of A=+5

b) Chemical formula of its chloride=ACl5

Explanation:

(a) Let the valency of element A be x, then 2x + 5(-2) = 0

As oxegen has a valency of =-2 and overall the compound must be neutral

x=10/2

So, x = valency of element A = 5

(b)(b) As valency of element A is 5 and valency of chlorine is -1,

So, the formula of chloride of A is ACl5.