Question

no of particles in 0.2 moles of hydrogen

Answer 1

1 mole of hydrogen gas have 6.022*10^23 molecule

so , 0.2 mole of it contains

6.022*10^23*0.2 moles of molecule

Answer 2

Molar mass of H2 is 2g

2g of H2 Contains $6.023\times10^{23} molecules

200mg = 0.2 g

0.2 g of H2 Contains --------?

=0.2×6.023×10232=6.023×1021 molecules

The number of molecules present in 0.2 g of H2is2.737×1021