Aspartame (C₁₄H₁₈N₂O₅) is a solid used as an artificial sweetener. its combustion produces carbon dioxide gas, liquid water, and nitrogen gas
C₁₄H₁₈N₂O₅ + 16O₂-----> 14CO₂ + 9H₂O + N₂.
As it can be seen from the equation, that the coefficient of nitrogen gas in the balanced equation for the reaction is 1.
So the answer here is 1 only that is coefficient of nitrogen gas in the balanced equation for the reaction is 1.