A flask contains `10^(20)` atoms of He (At. Mass =4) at S.T.P. (760 mm Hg pressure and 273.15 K). The number of `CO_(2)` molecules (Mol. Mass = 44) present in the same flask under similar conditions of temperature and pressure are

Options

A. `2.3xx10^(18)`
B. `2.2xx10^(20)`
C. `1.00xx10^(20)`
D. None of these

Answer

C

Explanation

According to Avogadro's law, equal volume of all gases under similar conditions of temperature and pressure contains equal number of molecules.