Chlorophyll contains 2.68% of magnesium metal by mass. Calculate the number of Mg atoms present in 2.0g of chlorophyll.

Explanation

Amount of Mg present in 2g of chlorophyll
`=(2.68)/(100)xx2=0.0536g`
Gram-atomic mass of Mg=24g
`therefore`Number of Mg-atoms in 24g=`6.022xx10^(23)`
`therefore`Number of atoms present in 0.0536g of Mg
`=(6.022xx10^(23))/(24)xx0.0536=1.345xx10^(21)`