During the Dumas method, the hot combustion gases are passed over a heated copper gauze before enter — Qualitative and Quantitative Analysis Chemistry Question

💡 Solution & Explanation

A small amount of nitrogen may be oxidized to oxides like $NO$ or $NO_2$ during heating with $CuO$. The hot copper gauze acts as a reducing agent to convert these oxides back to molecular $N_2$ ensuring accurate volumetric measurement.