Final answer:
Upon review, equation A) KClO3 → KCl + O2 is not balanced. It would need to be balanced by adding coefficients, such as 2KClO3 → 2KCl + 3O2, for it to adhere to the law of conservation of mass.
Step-by-step explanation:
To determine which of the following equations is not balanced, let's examine each one:
- A) 2KClO3 → 2KCl + 3O2 (This is the corrected version of the equation. Without the coefficients, it is not balanced.)
- B) MgI2 + Br2 → MgBr2 + I2 (This equation is already balanced.)
- C) O2 + 3H2 → 2NH3 (This equation is already balanced as well.)
- D) HCl + NaOH → NaCl + H2O (This equation is a typical representation of an acid-base neutralization and is balanced.)
In conclusion, option A is the one which is not balanced in its original form, requiring coefficients to ensure the same number of each element exists on both sides of the equation.