Final answer:
The original equation, 2NCl₃ → N₂ + Cl₂, is not balanced due to the number of chlorine atoms. By adding a coefficient of 3 to Cl₂, we obtain a balanced chemical equation: 2NCl₃ → N₂ + 3Cl₂.
Step-by-step explanation:
The chemical equation provided by the student, 2NCl₃ → N₂ + Cl₂, needs to be checked for balance to determine if it is a balanced chemical equation.
Upon inspecting the equation, we find a total of 6 chlorine (Cl) atoms on the reactant side (2 molecules of NCl₃ each with 3 Cl atoms), but only 2 chlorine atoms on the product side.
Similarly, there is just 1 nitrogen (N) molecule on the product side (which contains 2 N atoms), but the reactants have 2 nitrogen atoms from the 2 molecules of NCl₃.
Therefore, in terms of nitrogen, the equation is already balanced. The chlorine, however, is not balanced.
To balance it, add a coefficient of 3 in front of Cl₂ in the products, giving us 2NCl₃ → N₂ + 3Cl₂. This equation is now balanced for both elements with 2 nitrogen atoms and 6 chlorine atoms on each side, making it a balanced chemical equation.
Remember, it is important to recognize diatomic molecules in balancing equations, such as N₂ and Cl₂.