Question

Suppose the elements X and Y combine to form two compounds XY₂ and X₃Y₂. When 0.1 mole of XY₂ weighs 10 g and 0.05 mole of X₃Y₂ weighs 9 g, the atomic weights of X and Y are

(a) 40,30

(b) 60, 40

(c) 20, 30

(d) 30, 20

Answer 1

The correct option: (a) 40,30

Explanation

Let atomic weight of element X is x and that of element Y is y

On solving equations (i) and (ii), we get y = 30

x + 2(30) = 100 => x = 100 - 60 = 40