When the equation below is properly balanced, what coefficient is of KClO3? KClO3 → KCl + O2
a. 1
b. 2
c. 3
d. 4
The correct answer and explanation is:
The correct answer is b. 2.
Here’s how to balance the equation:
The unbalanced chemical equation is: KClO3→KCl+O2KClO_3 \rightarrow KCl + O_2
First, start by looking at the potassium (K) and chlorine (Cl) atoms. On the left side, there is one potassium (K) atom and one chlorine (Cl) atom in KClO3, and on the right side, one potassium (K) atom and one chlorine (Cl) atom in KCl. These are already balanced, so we don’t need to adjust the potassium or chlorine coefficients.
Next, focus on the oxygen atoms. On the left side, there are three oxygen atoms in KClO3, and on the right side, there are two oxygen atoms in O2. To balance the oxygen atoms, we need to find the smallest common multiple of 3 and 2, which is 6. So, we adjust the coefficients to balance the oxygen atoms.
On the left side, place a coefficient of 2 in front of KClO3, giving: 2KClO3→KCl+O22KClO_3 \rightarrow KCl + O_2
Now there are 6 oxygen atoms on the left side (2 × 3). To balance, place a coefficient of 3 in front of O2: 2KClO3→2KCl+3O22KClO_3 \rightarrow 2KCl + 3O_2
Finally, check the balance of all elements:
- Potassium: 2 on both sides.
- Chlorine: 2 on both sides.
- Oxygen: 6 on both sides (3 × 2 = 6).
Thus, the equation is now balanced with the correct coefficient of 2 for KClO3.