In this experiment, magnesium (Mg) exhibits a powerful affinity for oxygen, stealing it from dry ice (solid carbon dioxide) to form magnesium oxide (MgO) and carbon soot. The reaction accelerates, causing the light emitted to intensify until all the magnesium is consumed. Even when a dry ice lid is placed over the burning magnesium, cutting off its access to atmospheric oxygen, the reaction continues due to magnesium's eagerness to form stable magnesium oxide. The metal can extract oxygen not only from the air but also from sources like water, sand, and even carbon dioxide in dry ice. The chemical equation $2\text{ Mg (s)}+{\text{CO}}_2(\text{g})\to 2\text{ MgO (s)}+\text{C (s)}$ represents this reaction. Despite being cut off from atmospheric oxygen, the magnesium reacts with carbon dioxide as dry ice sublimes, releasing heat and light. After burning, white magnesium oxide and black carbon remain. The experiment underscores the importance of identifying the fire source before attempting to extinguish it, emphasizing that magnesium fires persist even in the presence of carbon dioxide, making traditional fire extinguishers ineffective.
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