One gram mole of a gas at N.T.P. occupies 22.4 litres. This fact was derived from

Option (c) Avogadro's hypothesis

Explanation

By definition of vapour density of a gas ,we know

Vapour density (D)

= mass of 1L gas at NTP,/mass of 1L Hydrogen at NTP

We know molecular wt M=2D

And by actual experiment the mass of 1L Hydrogen at NTP is 0.089g

So (M×0.089)g hydrogen occupies 1L at NTP

So 1gmole or Mg hydrogen will occupy 2/0.089=22.4L at NTP

Correct option  (c) Avogadro's hypothesis

Explanation:

According to Avogadro's hypothesis, equal volumes of different gases. contain same number of molecules under similar conditions of temperature and pressure. Thus, 22.4 litres of any gas at NTP will contain one gram mole or its molecular mass in grams.