Respuesta :

Molar mass NH3 = 17.031 g/mol

1 mole NH3 ---------- 17.031 g
?? moles -------------- 1.2x10³ g

moles NH3 =  1 x ( 1.2x10³  ) / 17.031

moles NH3 = 1.2x10³ / 17.031

= 70.45 moles of NH3

hope this helps!