The nitrogen content of organic compounds can be determined by the Dumas method. The compound in question is first reacted by passage over hot CuO
Compound N2(g) + CO2(g) + H2O(g)
The product gas is then passed through a concentrated solution of KOH to remove the CO2. After passage through the KOH solution, the gas contains N2 and is saturated with water vapor. In a given experiment a 0.271 g sample of a compound produced 31.8 mL N2 saturated with water vapor at 25°C and 726 torr. What is the mass percent of nitrogen in the compound? (The vapor pressure of water at 25°C is 23.8 torr.)
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Solve for pressure of N_2:
Total pressure = vp of H_2 O + vp of N_2
726 torr = 23.8 torr + vp of N_2
vp of N_2 = 702.2 ...
This solution provides all the steps for the given physical chemistry problem involving determining the nitrogen content of the given organic compounds.