Question

Suppose the elements X and Y combine to form two compounds XY2 and X3Y2 . When 0.2 mole of XY2 weighs 20 g and 0.1 mole of X3Y2 weighs 18 g , the atomic weights of Xand Y are​

Answer 1

Answer ⤵️

Let x and y be the atomic weights of X and Y

Given 0.1 mole of XY

2

weighs 10g

⇒x+2y=

0.1

10

=100⟶(1)

0.05 mole of X

3

Y

2

weighs 9g

⇒3x+2y=

0.05

9

=180⟶(2)

(1)⇒x=100−2y

Substituting for x in Equation (2)

⇒3(100−2y)+2y=180

⇒300−6y+2y=180

⇒y=30

Hence x=100−2(30)=40