The maximum number of molecules is present in :

Options

A. 1.5 L `H_(2)` gas at STP
B. 5 L `N_(2)` gas at STP
C. 0.5 g `H_(2)` gas
D. 10 g `O_(2)` gas.

Answer

A

Explanation

15 L `H_(2)` gas at STP
No. of moles `=15/22.4 = 0.2232`
No. of molecules `rArr 0.2232 xx N_(A)`
0.5 g `H_(2)` gas
No. of moles `=0.5/2 -0.25`
No. of molecules `=0.25 x N_(A)`
10 g `O_(2)` gas
No. of moles `=10/32 = 0.3125`
No. of molecules `=0.3125 xx N_(A)`