Question

The volume occupied by 53.5g.of Cl2. Cl2=35.5

Answer 1

1 mole of any gas occupies 22.4 L at STP 

i.e.

71 g of Cl2 = 22.4 L

So,

53.5 g of Cl2 = 22.4/71 × 53.5 = 16.88 L

Answer 2

mole=given weight/molecular mass
mole=53.5/35.5
mole=1.5