Nitric acid plus aluminum foil balanced equation.
a) 2Al + 6HNO₃ → 2Al(NO₃)₃ + 3H₂O + 3NO₂
b) 2Al + 4HNO₃ → 2Al(NO₃)₂ + 2H₂O + 3NO
c) 3Al + 3HNO₃ → 3Al(NO₃)₃ + 2H₂O + 2NO
d) 4Al + 6HNO₃ → 4Al(NO₃)₃ + 3H₂O + 3NO