`10^(21)` molecules are removed from 200 mg of `CO_(2)`.
The moles of `CO_(2)` left are:

Options

A. `2.88xx10^(-3)`
B. `28.8xx10^(-3)`
C. `28.8xx10^(-3)`
D. `28.8xx10^(3)`

Answer

A

Explanation

1 mole of `CO_(2)` molecule
`=6.023xx10^(23)` molecule of `CO_(2)`
`=44 g of CO_(2)`
`:. 10^(21)` molecules of `CO_(2)`
`=(44)/(6.023xx10^(23))xx10^(21) g CO_(2)`
`=7.31xx10^(-2)g=73.1 mg`
`:. CO_(2)` left `=200-73.1=126.9 mg`