Suppose the elements X and Y combine to formtwo compounds XY2 and X,Y2

1.	Suppose the elements X and Y combine to formtwo compounds XY2 and X,Y2: When 0.1 mole ofXY2 weighs 10 g and 0.05 mole of X3Y2 weighs9 g, the atomic weights of X and Y are[NEET-Phase-2-2016](1) 40, 30(3) 20, 30(2) 60, 40(4) 30, 20
Answer» Let atomic weight of x = Mxatomic weight of y = My we know, mole = weight /atomic weight a/c to question, mole of xy2 = 0.1 so, 0.1 = 10g/( Mx +2My) Mx + 2My = 100g -------(1) for x3y2 ; mole of x3y2 = 0.05 0.05 = 9/( 3Mx + 2My ) 3Mx + 2My = 9/0.05 = 9× 20 = 180 g ---(2) solve eqns (1) and (2) 2Mx = 80 Mx = 40g/mol and My = 30g/mole

Suppose the elements X and Y combine to formtwo compounds XY2 and X,Y2: When 0.1 mole ofXY2 weighs 10 g and 0.05 mole of X3Y2 weighs9 g, the atomic weights of X and Y are[NEET-Phase-2-2016](1) 40, 30(3) 20, 30(2) 60, 40(4) 30, 20

Answer»

Let atomic weight of x = Mxatomic weight of y = My

we know, mole = weight /atomic weight a/c to question,

mole of xy2 = 0.1 so, 0.1 = 10g/( Mx +2My)

Mx + 2My = 100g -------(1)

for x3y2 ; mole of x3y2 = 0.05

0.05 = 9/( 3Mx + 2My )

3Mx + 2My = 9/0.05 = 9× 20 = 180 g ---(2) solve eqns (1) and (2)

2Mx = 80 Mx = 40g/mol

and My = 30g/mole