Which of the following has the minimum mass?

Options

A. `6.02xx10^(22)H_(2)` molecules
B. `1120 c c` of `CO_(2)` at `STP`
C. `0.1` mol of `NH_(3)`
D. `0.1g` atom of carbon

Answer

A

Explanation

(1) `n_(H_(2)) = (6.02xx10^(22))/(6.02xx10^(23)) = 0.1` mol
`:. M_(H_(2)) = (0.1 mol) (2g mol^(-1)) = 0.2g`
(2) `n_(CO_(2))=(1120 c c)/(22400c c"mol"^(-1))=0.05"mol"`
`:. M_(CO_(2)) = (0.05 "mol") (44g "mol"^(-1)) = 2.2g`
(3) `m_(NH_(3)) = (0.1 "mol") (17g "mol"^(-1)) = 1.7g`
(4) `0.1g` atom of `C = 0.1` mol
`= (0.1 "mol") (12 g "mol"^(-1)) = 1.25`