_Mg(C103)2(s) -> _MgCl2(s)+_02(g)

What is the coefficient of 02 when the equation is balanced correctly using the smallest whole-number coefficients?

What problem are you having balancing equations. You need to learn to do these yourself.

To balance the given chemical equation "Mg(ClO3)2(s) -> MgCl2(s) + O2(g)", we need to ensure that the number of atoms of each element is the same on both sides of the equation.

Here's how we can balance the equation step by step:

1. Start by counting the number of atoms on each side:
Left side (reactants):
- Magnesium (Mg): 1
- Chlorine (Cl): 2
- Oxygen (O): 6

Right side (products):
- Magnesium (Mg): 1
- Chlorine (Cl): 2
- Oxygen (O): 2

2. Balance the atoms other than oxygen and hydrogen first:
The number of Mg and Cl atoms is already balanced, so we can move on to balancing the oxygen atoms.

3. Balance the oxygen atoms:
Since there are 6 oxygen atoms on the left side and only 2 on the right side, we need to add a coefficient in front of O2 to balance the oxygen atoms. Let's use the coefficient 3 in this case, which would give us 3 O2 on the right side.

The final balanced equation is:
Mg(ClO3)2(s) -> MgCl2(s) + 3 O2(g)

Therefore, the coefficient of O2 in the balanced equation is 3.