Question

The simplest formula of a compound containing 50% of element of X (atomic mass = 10) and 50% of element Y (atomic mass = 20) by weight is :
(A) XY
(B) X2Y
(C) XY3
(D) X2Y3

Answer 1

X2Y is the correct answer.....
Hope it will help you

Answer 2

Moles of X = 50/10

                   = 5

Moles of Y = 50/20

                  = 2.5

X:Y = 2:1

Hence, X2Y is the correct option.