Which molecule contains the smallest number of hydrogen atoms? a) n2h4. b) al(oh) 3. c) (nh4) 2so4. d) nh4no3.

Option (B) is the correct answer.

Explanation:

In a molecule of , there are 2 nitrogen atoms and 4 hydrogen atoms.  

In a molecule of , there are one aluminium atom, three oxygen atoms, and three hydrogen atoms.

In a molecule of , there are 2 nitrogen atoms, 8 hydrogen atoms, one sulfur atom and 4 oxygen atoms.

In a molecule of , there are 2 nitrogen atoms, 4 hydrogen atoms and 3 oxygen atoms.  

Therefore, we can conclude that out of the given options is the molecule which contains the smallest number of hydrogen atoms.