Final answer:
The unbalanced equation 2NaN3 → 2Na + N2 does not have the same number of nitrogen atoms on both sides. It should be balanced as 2NaN3 → 2Na + 3N2 to comply with the law of conservation of mass.
Step-by-step explanation:
Balancing a Chemical Equation
The chemical equation 2NaN3 → 2Na + N2 is unbalanced. In the reactants, there are 6 nitrogen atoms (2 molecules of NaN3, each containing 3 nitrogen atoms) and 2 sodium atoms. However, on the product side, there are only 2 nitrogen atoms (in one molecule of N2) and 2 sodium atoms. To balance the equation, we cannot change the chemical formulas of the substances but can adjust the coefficients to ensure that the number of atoms of each element is equal on both sides of the equation. The correct balanced equation should read 2NaN3 → 2Na + 3N2, indicating that 2 moles of sodium azide yield 2 moles of sodium metal and 3 moles of diatomic nitrogen gas, thus preserving the law of conservation of mass.