The nitrogen content of organic compounds can be determined by the Dumas method. The compound in question is first passed over hot CuO(s): Compound + Hot CuO(s)------> N2(g) + CO2(g) + H2O(g) The gaseous products are then passed through a concentrated aqueous KOH solution to remove the CO2. The remaining gas contains N2 and water vapor. A 0.648-g sample of a compound was treated as above, producing 82.7 mL of N2 saturated with water vapor at 25 °C and 778.3 torr. What is the mass percent of nitrogen in the compound? (The vapor pressure of water at 25 °C is 23.8 torr.)
Thermochemistry
Thermochemistry can be considered as a branch of thermodynamics that deals with the connections between warmth, work, and various types of energy, formed because of different synthetic and actual cycles. Thermochemistry describes the energy changes that occur as a result of reactions or chemical changes in a substance.
Exergonic Reaction
The term exergonic is derived from the Greek word in which ‘ergon’ means work and exergonic means ‘work outside’. Exergonic reactions releases work energy. Exergonic reactions are different from exothermic reactions, the one that releases only heat energy during the course of the reaction. So, exothermic reaction is one type of exergonic reaction. Exergonic reaction releases work energy in different forms like heat, light or sound. For example, a glow stick releases light making that an exergonic reaction and not an exothermic reaction since no heat is released. Even endothermic reactions at very high temperature are exergonic.
The nitrogen content of organic compounds can be determined by the Dumas method.
The compound in question is first passed over hot CuO(s):
| Compound + Hot CuO(s)------> N2(g) + CO2(g) + H2O(g) |
The gaseous products are then passed through a concentrated aqueous KOH solution to remove the CO2.
The remaining gas contains N2 and water vapor.
A 0.648-g sample of a compound was treated as above, producing 82.7 mL of N2 saturated with water vapor at 25 °C and 778.3 torr.
What is the mass percent of nitrogen in the compound? (The vapor pressure of water at 25 °C is 23.8 torr.)
Step by step
Solved in 3 steps
