Calculate the number of moles for the following:
(i) 52 g of He (finding mole from mass)
(ii) `12.044 × 10_(23)` number of He atoms (finding mole from number of particles).

Explanation

(i)52g of He
`"No. of moles"=("Given mass (m)")/("Gram atomic mass (M)")=((52g))/((4g))=13"mol"`
(ii) `12.044xx10^(23)"atoms of He"`
`"No. of moles"=("No. of atoms of helium")/("Avogadro's no. of atoms")=((N))/((N_(0)))=(12.044xx10^(23))/(6.022xx10^(23))=2"mol"`