How Does The Hydrochloric Acid Affect The Reaction Rate Of Reaction

Before we start the calculations, we can tell that Al is the element being oxidized, since the oxidation number increased from 0 to +3 after the reaction. The element that was reduced is N because it went from +3 to -3 after the reaction. N is also the oxidizing agent because it acts in the reactant that is the oxidizing agent. The reducing agent is Al because it acts in the reactant that is the reducing agent.

Calculations:
Oxidation half reaction = Al + AlO2^-
Reduction half reaction = NO2^- + NH3

Balance all other atoms except hydrogen and oxygen:
Al = AlO2^-

NO2^- = NH3

Balance the oxygen atoms:
Al + 2H2O = AlO2^-

NO2^- = NH3 + 2H2O

Balance Hydrogen atoms:
Al + 2H2O = AlO2^- + 4H^+

NO2^- + 7H^+ = NH3 + 2H2O

Balance the total charge: