Which of the following pairs have the same number of atoms ?

Options

A. 16 g of `O_(2)`(g) and 4 g of `H_(2)`(g)
B. 16 g of `O_(2)` and 44 g of `CO_(2)`
C. 28 g of `N_(2)` and 32 g of `O_(2)`
D. 12 f of C(s) and 23 g of Na(s)

Answer

C, D

Explanation

16 g `O_(2) = 16/32 = 0.5` mol
`=2 xx 0.5 xx N_(A)` atoms `=N_(A)` atoms
4g `H_(2) = 4/3 =2` mol
`=2 xx 2 xx N_(A)` atoms `=4N_(A)` atoms
44 g `CO_(2) = 44/44 =1` mol
`=3 xx 1 xx N_(A)` atoms = `3N_(A)` atoms
28 g `N_(2) = 28/28=1` mol
`=2 xx 1 xx N_(A)` atoms `=2N_(A)` atoms
32 g of `O_(2) = 32/32=1` mol
`=1 xx 2 xx N_(A)` atoms `=2N_(A)` atoms
12 g C `=12/12=1` mol `=N_(A)` atoms
23 g of Na `=23/23=1` mol `=N_(A)` atoms
`therefore` (c) and (d) are correct.