Question

Find the ratio of number of atoms present in 16 g of O2 and 32 g of O3.

1 ) 1:1
2) 2:1
3) 1:3
4) 1:2

Answer 1

Number of atom = moles x Avogadro's number x atomicity

Moles of O2 = 16/32
= 1/2
Moles of O3 = 32/48
=2/3

No. of atom of O2/ No. of atom of O3 =( 1/2 x Na x 2)/(2/3 x Na x 3)

Ratio will be= 1/2......(4)

Here Na = Avogadro's number
atomicity = total number of atom present in a molecule.

Answer 2

No. Of atoms = given mass /

molecular mass

For 02

16/16*2= 16/32

= 1/2*2 ( *2 because nUmber of atom

are 2 in O2)

=1

Similarly for O3,

32/48= 2/3*3 =2

O2/O3 = 1/3

1:3 answer