During the Dumas method for the quantitative estimation of nitrogen, the hot combustion gases are in — Qualitative and Quantitative Analysis Chemistry Question

💡 Solution & Explanation

During the high-temperature oxidation with $CuO$, a small fraction of the organic nitrogen may be oxidized into oxides of nitrogen (e.g., $NO, NO_2$). The heated copper gauze acts as a crucial reducing agent, converting these oxides back to elemental $N_2$ gas to ensure an accurate volumetric measurement.