Chlorophyll, the green colouring matter of plants responsible for photosynthesis contains 2.68 % of magnesium by mass. The number of magnesium atoms in 2.00 g of chlokrophyll are

Options

A. `1.33xx10^(23)`
B. `6.02xx10^(23)`
C. `3.01xx10^(21)`
D. `1.34xx10^(21)`

Answer

D

Explanation

Mass of magnesium `= (2.00xx2.68)/(100)`
`= 5.36xx10^(-2)g`
24 g of Mg `= 6.02xx10^(23)` atoms
`:. 5.36xx10^(-2)` g of Mg
`= (6.02xx10^(23)"atoms")xx((5.36xx10^(-2)g)/(24g))`
`=1.34xx10^(21)` atoms