Which has maximum number of molecules?
(a) 7g N2
(b) 2g H2
(c) 16g NO2
(d) 16g O2
(b) In 7g nitrogen, number of molecules = mol = 0.25 x NA molecules
where, NA = Avogadro number = 6.023 x 1023
In 2g of H2= 2/2 mol =1x NA molecules
In 16 g of NO2= 16/46 mol = 0.348 x NA molecules
In 16 g of O2 = 16/32 mol = 0.5 x NA molecules
Hence, maximum number of molecules are present in 2g of H2.