Dumas Method (Nitrogen Estimation) (Organic compound + CuO → N₂ (collected over KOH) + CO₂ + H₂O)
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Organic compound + CuO → N₂ (collected over KOH) + CO₂ + H₂O
What each symbol means
| Symbol | What it stands for |
|---|---|
| CuO | Copper(II) oxide — oxidant that converts C→CO₂, H→H₂O, N→N₂ |
| Cu gauze | Reduces any NOₓ back to N₂ |
| KOH solution | Absorbs CO₂; only N₂ remains (measured volumetrically) |
When to use this
Compound heated with excess CuO in CO₂ atmosphere. Gaseous products passed over Cu gauze (reduces NOₓ→N₂), then over KOH (absorbs CO₂). Residual gas = pure N₂ measured volumetrically at STP.