How many liters of ammonia are produced when 3.0 moles of water and 3.0 moles of nitrogen dioxide are reacted to completion at stp conditions

The  number  of  ammonia  in liters   produced  is  calculated  as  follows

write  the  reacting  equation

4NO2 +6H2O  = 4NH3  + 7 O
H2O  is  the limiting   reactant  since 3 moles  of H20  reacted   completely  with   3 x4/6 = 2  moles  of NO2

At   STP  1 mole =  22.4  L  what about  2 moles

=  2 / 1 x22.4  =44.8  liters of ammonia

Ibelieve its a because an empirical formula usually has a ch in it your options are a or b