1kmol 63kg 18kg
C₆H₆ + HNO₃ -> C₆H₅-NO₂ + H₂O
1kmol a=63kg b=18kg
in urma reactiei, 63kg de HNO₃ nitreaza benzenul, diluand amestecul nitrant ramas cu 18kg apa
masa amestecului nitrant ramas = 400-63+18=355kg amestec nitrant final
mHNO₃initial=30% din 400kg=0,3*400=120kg HNO₃
mHNO₃ramasa=120-63=57kg HNO₃
%HNO₃=57*100%/355=16,05%