Question

A compound is made up of two elements X and Y in the ratio 2:3 by mass. How many atoms of each of these elements would be present in the molecules of the compound? Give the molecular formula of the compound.

Answer 1

Answer:

ANSWER

Molarmass

Mass

=Mole

mw

5g

=0.05⇒mw=100

x+2y=100...(i)

6×10

23

No.ofmolecules

=

mw

mass

eq(1)×2

6.023×10

23

3.011×10

23

=

mw

85

⇒mw=170

2x+3y=170....(ii)

On solving equation (i) and (ii), we get-

2x+4y=200

2x+3y=170

y=30

2×x+3×30=170

2x=170−90

2x=80

x=40

So, the correct option is C