Chlorine is heated with oxygen to form dichlorine monoxide gas. Express your answer as a chemical equation. Identify all of the phases in your answer.

4 HCl (g) + O₂ (g) → 2 Cl₂ (g) + 2 H₂O (l)

Explanation:

4 moles of hydrogen chloride (note that it is in the gaseous phase, otherwise it would be hydrochloric acid) react with 1 mole of oxygen gas to form 2 moles of chlorine gas and 2 moles of liquid water.

To conform with  the law of conservation of mass, the equation must be balanced, this means that there must be the same number of each type of atom  on both sides of the arrow.

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c (diamond),

sio2 (quartz)