Question

what is the value of gram molecular volume of ozone at S.T.P?

Answer 1

Volume of any gas at STP is 22.4L

“Gram Molecular Volume” doesn’t makes any sense. I think you mean “Gram Molecular weight”

Gram Molecular weight of ozone is 48g/mol

Answer 2

Gram molecular volume is used to refer to the volume occupied by one molecule of a gas at a given temperature and pressure.

It is a known fact that the gram molecular volume of any gas at STP is 22.4 liters.

Ozone is a gas. Therefore, the gram molecular volume of ozone at STP is 22.4 liters.