Answer:
- Ca(ClO₃)₂ (s) → CaCl₂ (s) + 3O₂ (g)
Explanation:
1)<u> Word equation (given)</u>
- <em>calcium chlorate (solid) → solid calcium chloride (solid) + oxygen (gas)</em>
2) <u>Chemical formulae of the reactant and products</u>:
- <em><u>Calcium chlorate</u></em><em>: </em>
The most common oxidation states of chlorine are -1, +1, +3, +5, +7.
The suffix ate in chlorate means that chlorine atom is with the third lowest oxidation state (counting only the positive states). So, this is +5.
The oxidation state of calcium is +2.
Hence, the chemical formula of calcium chlorate is Ca(ClO₃)₂
- <u><em>Calcium chloride</em></u>
The suffix ide in chloride means that chlorine is with oxidation state -1. Again the oxidation state of calcium is +2.
Hence, the chemical formula of calcium chloride is CaCl₂
Oxygen gas is a diatomic molecule, so its chemical formula is O₂.
The symbols s and g (in parenthesis) indicate the solid and gas phases respectively.
3) <u>Chemical equation</u>:
- Ca(ClO₃)₂ (s) → CaCl₂ (s) + O₂ (g)
That equation is not balanced becasue the number of O atoms in the reactant side and in the product side are different.
4)<u> Balanced chemical equation:</u>
Add a 3 as coefficient in front of O₂(g), in the product side to balance:
- Ca(ClO₃)₂ (s) → CaCl₂ (s) + 3O₂ (g)
Verify that all the atoms are balanced:
Atom Reactant side Product side
Ca 1 1
Cl 2 2
O 3×2 = 6 2×3 = 6
Conclusion: the equation is balanced and the final answer is:
- Ca(ClO₃)₂ (s) → CaCl₂ (s) + 3O₂ (g)
